This site is supported by donations to The OEIS Foundation.

90

From OeisWiki
Jump to: navigation, search


This article is under construction.            

Please do not rely on any information it contains.            


90 is an integer.

Membership in core sequences

Even numbers ..., 84, 86, 88, 90, 92, 94, 96, ... A005843
Composite numbers ..., 86, 87, 88, 90, 91, 92, 93, ... A002808
Abundant numbers ..., 80, 84, 88, 90, 96, 100, 102, ... A005101
Oblong numbers ..., 42, 56, 72, 90, 110, 132, 156, ... A002378
Quarter-squares ..., 64, 72, 81, 90, 100, 110, 121, ... A002620
Numbers that are the sum of two squares ..., 82, 85, 89, 90, 97, 98, 100, ... A001481
Large Schröder numbers 1, 2, 6, 22, 90, 394, 1806, 8558, ... A006318

Sequences pertaining to 90

Multiples of 90 0, 90, 180, 270, 360, 450, 540, 630, ...
Divisors of 90 1, 2, 3, 5, 6, 9, 10, 15, 18, 30 A018278

Partitions of 90

There are 56634173 partitions of 90.

The Goldbach representations of 90 are: 83 + 7 = 79 + 11 = 73 + 17 = 71 + 19 = 67 + 23 = 61 + 29 = 59 + 31 = 53 + 37 = 47 + 43 = 90.

Values for number theoretic functions with 90 as an argument

PLACEHOLDER

Factorization of 90 in some quadratic integer rings

As was mentioned above, 90 is the product of four primes (three distinct) in . But in some quadratic integer rings, some of these primes are further reducible.

2 × 3 2 × 5
2 × 3 2 × 5 2 × 3 2 × 5
2 × 3 2 × 5
2 × 3 2 × 5

Representation of 90 in various bases

Base 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Representation 1011010 10100 1122 330 230 156 132 110 90 82 76 6C 66 60 5A 55 50 4E 4A

See also

Some integers
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29
30 31 32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47 48 49
1729