Cool Number Systems

Just a compilation of a bunch of neat number systems I've found or made.

The basics

The systems showcased will follow a few basic rules:

wikipedia - Numeral system

Every system showcased will have numbers shown in a table with decimal (base ten) digits on the left, and the system's digits on the right


Many systems showcased will use positional notation or variations of the idea.

n = column number (ex: hundreds place)

b = base number (ex: base ten)

... + (n × b3) + (n × b2) + (n × b1) + (n × b0)


ex:

The number "2508" in base 6 could be represented as:

(2 × 63) + (5 × b6) + (0 × 61) + (8 × b0)

wikipedia - Positional notation

System 1

0
1 1
2 11
3 111
4 1111
5 11111
6 111111
7 1111111
8 11111111
9 111111111
10 1111111111
11 11111111111
12 111111111111
13 1111111111111
14 11111111111111
15 111111111111111
16 1111111111111111
17 11111111111111111
18 111111111111111111
19 1111111111111111111
20 11111111111111111111
21 111111111111111111111
22 1111111111111111111111
23 11111111111111111111111

Base 1 (Unary)

Unary is the simplest number system, it's representing a number with the same amount of characters.

The closest thing that we currently use is tally marks, with the only difference grouping into 5s for countability.

The biggest downside of unary is of course that it can't represent large numbers readably.

wikipedia - Unary numeral system

System 10

0 0
1 1
2 10
3 11
4 100
5 101
6 110
7 111
8 1000
9 1001
10 1010
11 1011
12 1100
13 1101
14 1110
15 1111
16 10000
17 10001
18 10010
19 10011
20 10100
21 10101
22 10110
23 10111
24 11000
25 11001
26 11010
27 11011
28 11100
29 11101
30 11110
31 11111
32 100000
33 100001
34 100010
35 100011


64 1000000

Base 2 (Binary)

Other than decimal, this is the most well known system on this list, being used in computer science.

Being based around the number 2, the system makes itself very universal and applicable to a lot of problems.

This is my personal favorite base, see this fantastic video for a great argument for human usability

wikipedia - Binary number

System 3

0 0
1 1
2 2
3 3
4 4
5 10
6 11
7 12
8 13
9 14
10 20
11 21
12 22
13 23
14 24
15 30
16 31
17 32
18 33
19 34
20 40
21 41
22 42
23 43
24 44
25 100
26 101
27 102
28 103
29 104
30 110
31 111
32 112
33 113
34 114
35 120


125 1000

Base 5 (Quinary)

A system based around 5's should be somewhat more familliar to decimal users.

Interestingly, because it's an odd numbered base, 10 is an odd number, while 20 is even, the places switch back and forth accordingly.

wikipedia - Quinary

System 10000

0 0
1 1
2 100
3 101
4 10000
5 10001
6 10100
7 10101
8 1000000
9 1000001
10 1000100
11 1000101
12 1010000
13 1010001
14 1010100
15 1010101
16 100000000
17 100000001
18 100000100
19 100000101
20 100010000
21 100010001
22 100010100
23 100010101

Base √2

This is the first "cursed base" as I'll call it, with the base number being a square root.

Like many sytems on this list, this is mostly just a mathmatical side effect rather than a human usable base.

powers of √2 flip-flops between rational and irrational: (1, √2, 2, 2√2, 4, etc...) so only every other number is used to represent integers.

It ends up just looking like spaced out binary with zeros filling in the gaps.

wikipedia - Non-integer base of numeration

System 101

0 0
1 1
2 110
3 111
4 100
5 101
6 11010
7 11011
8 11000
9 11001
10 11110
11 11111
12 11100
13 11101
14 10010
15 10011
16 10000
17 10001
18 10110
19 10111
20 10100
21 10101
22 1101010
23 1101011
24 1101000
25 1101001
26 1101110
27 1101111
28 1101100
29 1101101
30 1100010
31 1100011
32 1100000
33 1100001
34 1100110
35 1100111

Base -2 (Negabinary)

I quite enjoy how unique this one ends up looking, with numbers having to cancel out.

Powers of -2 flip-flop between positive and negative: (1, -2, 4, -8, 16, etc...)

In order to write something like 8, it has to be -8 + 16.

wikipedia - Negative base

System 1-0

0 0
1 1
2 1-
3 10
4 11
5 1--
6 1-0
7 1-1
8 10-
9 100
10 101
11 11-
12 110
13 111
14 1---
15 1--0
16 1--1
17 1-0-
18 1-00
19 1-01
20 1-1-
21 1-10
22 1-11
23 10--
24 10-0
25 10-1
26 100-
27 1000
28 1001
29 101-
30 1010
31 1011
32 1---
33 1--0
34 1--1
35 1-0-


81 10000

Base 3 (Balanced Ternary)

While this one is very similar to base 3, it has the cool property of incorporating negatives.

In essence the system is just base 3 with the 2 replaced with -1.

It counts up very similar to a normal base, but with digit places halfway to the power of 3.

The system has a cool property where negative numbers are just positives when you swap 1 and - .

wikipedia - Balanced ternary

System 1000

0
1 0
2 1
3 10
4 2
5 100
6 11
7 1000
8 3
9 20
10 101
11 10000
12 110
13 100000
14 1001
15 110
16 4
17 1000000
18 21
19 10000000
20 102
21 1010
22 10001
23 100000000
24 13
25 200
26 100001
27 30
28 1002
29 1000000000
30 111
31 10000000000
32 5
33 10010
34 1000001
35 1100


37 100000000000
41 1000000000000
64 6

Prime number multiplying system

This one is a system of my creation, its built around prime multiplication.

Its a neat fact of primes that you can form any integer by multiplying them.

This system takes full advantage of this to have each digit place represent a given prime.

Its actually pretty useful for visualizing the make up of numbers, but is terrible for addition.

wikipedia - Fundamental theorem of arithmetic

System 110

0 0
1 1
2 10
3 11
4 20
5 21
6 100
7 101
8 110
9 111
10 120
11 121
12 200
13 201
14 210
15 211
16 220
17 221
18 300
19 301
20 310
21 311
22 320
23 321
24 1000
25 1001
26 1010
27 1011
28 1020
29 1021
30 1100
31 1101
32 1110
33 1111
34 1120
35 1121


119 4321
120 10000

Factorial (factoradic)

This one is interesting because it gets a new symbol every digit place.

It goes perfectly with the joke that bigger numbers should get the biggest number symbols.

Interesting while the only rule is that each place is worth the place factorial, it also ends up with each digit place being its own number base.

wikipedia - Factorial number system

System 3.1

0 0
1 1
2 2
3 3
4 4
5 5
6 0.1
7 1.1
8 2.1
9 3.1
10 4.1
11 5.1
12 0.2
13 1.2
14 2.2
15 3.2
16 4.2
17 5.2
18 0.3
19 1.3
20 2.3
21 3.3
22 4.3
23 5.3
24 0.4
25 1.4
26 2.4
27 3.4
28 4.4
29 5.4
30 0.5
31 1.5
32 2.11
33 3.5
34 4.5
35 5.5


36 0.01
216 0.001

Base 1/6

This system is unique in the aspect that its just one over base 6.

It ends up as base 6 with all the digits flipped around to be past the decimal point.

This is because the fractional base cancels out the negative power.

wikipedia - Senary

System 10202

0 0
1 1
2 2
3 3
4 10300
5 10301
6 10302
7 10303
8 10200
9 10201
10 10202
11 10203
12 10100
13 10101
14 10102
15 10103
16 10000
17 10001
18 10002
19 10003
20 20300
21 20301
22 20302
23 20303
24 20200
25 20201
26 20202
27 20203
28 20100
29 20101
30 20102
31 20103
32 20000
33 20001
34 20002
35 20003

Base 2i (Base √-4)

Since imaginary numbers are mathmatically just the square root of a negative number, the base gains the properties of both the square root base, and the negative base.

It has the same count down thing as the negative and the same spacing as the root.

wikipedia - Quater-imaginary base

System ~101.0110

0 0.0000
1 1.0000
2 2.0000
3 3.0000
4 ~10.2202
5 ~11.2202
6 ~12.2202
7 ~20.2021
8 ~21.2021
9 ~22.2021
10 ~100.0102
11 ~101.0110
12 ~102.0110
13 ~103.0110
14 ~110.3010
15 ~111.3010
16 ~112.3010
17 ~120.2200
18 ~121.2201
19 ~122.2201
20 ~200.0212
21 ~201.0212
22 ~202.0212
23 ~210.0102

Base π (pinary)

This is another cursed one because it ends up as having all integers being an approximation.

Pi is more than 3 so we need a 3 to get to the point that we can use the second digit place.

As terrible as it is, its really just a classic positional notation base.

wikipedia - Non-integer base of numeration

System 41

0 0
1 1
2 2
3 10
4 11
5 12
6 20
7 21
8 22
9 30
10 31
11 32
12 40
13 41
14 42
15 50
16 51
17 52
18 60
19 61
20 62
21 70
22 71
23 72
24 80
25 81
26 82
27 100
28 101
29 102
30 110
31 111
32 112
33 120
34 121
35 122


7625597484987 1000

Base 3 Tetration system (Tetrary 3)

This one uses the same idea as positional notation, but uses tetration instead of exponentiation.

Base 3 was a nice size (relatively) and is as such: 03, 13, 23, 33 or 1, 3, 27, 7625597484987.

It starts out using reasonably sized numbers, but very quickly gets out of hand in symbol count.

wikipedia - Tetration

Hey, thanks for reading. Nothing here is too serious, just some fun number systems I've found. Hope this page was interesting, have a good one.