Expansion of Product_{k>=1} (1 + x^k)^binomial(k+3,3).

Terms

a(0) =1a(1) =4a(2) =16a(3) =64a(4) =221a(5) =736a(6) =2338a(7) =7132a(8) =21093a(9) =60652a(10) =170172a(11) =467140a(12) =1257571a(13) =3325824a(14) =8654576a(15) =22189340a(16) =56116043a(17) =140122760a(18) =345769094a(19) =843827436a(20) =2038017983a(21) =4874329024a(22) =11550814704a(23) =27134195608a(24) =63215468883a(25) =146120097736a(26) =335227455982a(27) =763592477104