156145

Appears in sequences

• G.f.: exp( Sum_{n>=1} x^n/n * Product_{k>=1} (1 + x^(n*k)*(1 + x^k)^n) ).at n=23A218576
• 28-gonal pyramidal numbers: a(n) = n*(n+1)*(26*n-23)/6.at n=33A256648
• Square array A(n,k), n>=0, k>=0, read by antidiagonals downwards, where column k is the expansion of 1/(1 - k*x) * Product_{j=0..k-1} (1 + j*x)/(1 - j*x).at n=60A383818
• a(n) = [x^n] 1/(1 - n*x) * Product_{k=0..n-1} (1 + k*x)/(1 - k*x).at n=5A383839