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

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =14a(5) =25a(6) =45a(7) =77a(8) =131a(9) =224a(10) =377a(11) =629a(12) =1049a(13) =1738a(14) =2863a(15) =4708a(16) =7716a(17) =12598a(18) =20524a(19) =33363a(20) =54102a(21) =87567a(22) =141489a(23) =228216a(24) =367538a(25) =591098a(26) =949372a(27) =1522917a(28) =2440190a(29) =3905747