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

Terms

a(0) =1a(1) =1a(2) =3a(3) =4a(4) =7a(5) =10a(6) =16a(7) =22a(8) =34a(9) =46a(10) =67a(11) =90a(12) =126a(13) =167a(14) =228a(15) =299a(16) =399a(17) =518a(18) =681a(19) =874a(20) =1134a(21) =1443a(22) =1848a(23) =2334a(24) =2959a(25) =3708a(26) =4661a(27) =5801a(28) =7233a(29) =8947