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

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =8a(5) =12a(6) =17a(7) =24a(8) =33a(9) =46a(10) =62a(11) =82a(12) =108a(13) =141a(14) =182a(15) =233a(16) =297a(17) =375a(18) =472a(19) =590a(20) =733a(21) =907a(22) =1117a(23) =1369a(24) =1671a(25) =2034a(26) =2465a(27) =2978a(28) =3586a(29) =4304