Expansion of Product_{k>=1} (1+x^k)^(k*(k+1)).

Terms

a(0) =1a(1) =2a(2) =7a(3) =24a(4) =65a(5) =184a(6) =487a(7) =1254a(8) =3145a(9) =7706a(10) =18480a(11) =43490a(12) =100692a(13) =229472a(14) =515802a(15) =1144416a(16) =2508948a(17) =5439642a(18) =11671859a(19) =24801738a(20) =52221911a(21) =109013538a(22) =225718717a(23) =463769652a(24) =945915199a(25) =1915895576a(26) =3854803572a(27) =7706786958a(28) =15314564282a(29) =30255672820