G.f.: 1/Product_{k>=1} (1 - x^(2*k^2)) * (1 - x^k).

Terms

a(0) =1a(1) =1a(2) =3a(3) =4a(4) =8a(5) =11a(6) =19a(7) =26a(8) =42a(9) =57a(10) =86a(11) =116a(12) =168a(13) =224a(14) =314a(15) =415a(16) =568a(17) =743a(18) =998a(19) =1293a(20) =1709a(21) =2196a(22) =2862a(23) =3649a(24) =4702a(25) =5950a(26) =7590a(27) =9540a(28) =12061a(29) =15064