Expansion of Product_{k>=1} (1 + x^k)^(k^2*(k+1)/2).

Terms

a(0) =1a(1) =1a(2) =6a(3) =24a(4) =73a(5) =238a(6) =722a(7) =2175a(8) =6343a(9) =18177a(10) =50982a(11) =140671a(12) =382227a(13) =1023623a(14) =2706184a(15) =7067324a(16) =18250671a(17) =46635309a(18) =117997008a(19) =295794098a(20) =735030985a(21) =1811435607a(22) =4429226677a(23) =10749552338a(24) =25903858181a(25) =62000039513a(26) =147435739522a(27) =348431110651a(28) =818549931526