Expansion of Sum_{n>=1} x^(n*(n+1)/2)*((1+x)/(1-x))^n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =10a(5) =15a(6) =24a(7) =40a(8) =64a(9) =97a(10) =144a(11) =216a(12) =328a(13) =496a(14) =737a(15) =1074a(16) =1546a(17) =2218a(18) =3186a(19) =4578a(20) =6555a(21) =9318a(22) =13130a(23) =18358a(24) =25530a(25) =35398a(26) =49002a(27) =67735a(28) =93416a(29) =128392