Partition Number Calculator

Calculate p(n), the number of ways to write n as a sum of positive integers.

Calculate p(n)

p(10)

42

All partitions

q(10)

10

Distinct parts only

Odd parts

10

= q(n) (Euler)

Partition Sequence

p(0)=1p(1)=1p(2)=2p(3)=3p(4)=5p(5)=7p(6)=11p(7)=15p(8)=22p(9)=30p(10)=42

Partitions of 10

10
9 + 1
8 + 2
8 + 1 + 1
7 + 3
7 + 2 + 1
7 + 1 + 1 + 1
6 + 4
6 + 3 + 1
6 + 2 + 2
6 + 2 + 1 + 1
6 + 1 + 1 + 1 + 1
5 + 5
5 + 4 + 1
5 + 3 + 2
5 + 3 + 1 + 1
5 + 2 + 2 + 1
5 + 2 + 1 + 1 + 1
5 + 1 + 1 + 1 + 1 + 1
4 + 4 + 2
4 + 4 + 1 + 1
4 + 3 + 3
4 + 3 + 2 + 1
4 + 3 + 1 + 1 + 1
4 + 2 + 2 + 2
4 + 2 + 2 + 1 + 1
4 + 2 + 1 + 1 + 1 + 1
4 + 1 + 1 + 1 + 1 + 1 + 1
3 + 3 + 3 + 1
3 + 3 + 2 + 2
3 + 3 + 2 + 1 + 1
3 + 3 + 1 + 1 + 1 + 1
3 + 2 + 2 + 2 + 1
3 + 2 + 2 + 1 + 1 + 1
3 + 2 + 1 + 1 + 1 + 1 + 1
3 + 1 + 1 + 1 + 1 + 1 + 1 + 1
2 + 2 + 2 + 2 + 2
2 + 2 + 2 + 2 + 1 + 1
2 + 2 + 2 + 1 + 1 + 1 + 1
2 + 2 + 1 + 1 + 1 + 1 + 1 + 1
2 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1
1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1

Properties

Euler's Identity

Number of partitions into distinct parts = partitions into odd parts

Generating Function

Σp(n)x^n = Π 1/(1-x^k)

Hardy-Ramanujan

p(n) ~ exp(π√(2n/3)) / (4n√3)

Pentagonal Theorem

p(n) = Σ (-1)^(k+1) p(n - k(3k-1)/2)