Adi Dani
16,347
reputation
4
26
51
Euler formula for partition function
$p(n)=\sum_{k=1}^{\infty}(-1)^{k+1}\left(p\left(n-\frac{k(3k-1)}{2}\right)+ p\left(n-\frac{k(3k+1)}{2}\right)\right)$