a(n) = [x^n] Product_{k>=1} 1/(1 - k*x^k)^n.

Terms

a(0) =1a(1) =1a(2) =7a(3) =37a(4) =219a(5) =1276a(6) =7687a(7) =46551a(8) =285043a(9) =1756243a(10) =10883842a(11) =67751289a(12) =423366831a(13) =2654041235a(14) =16683909711a(15) =105129718102a(16) =663837626163