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

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =1a(5) =0a(6) =1a(7) =2a(8) =7a(9) =0a(10) =1a(11) =2a(12) =1a(13) =0a(14) =7a(15) =26a(16) =1a(17) =0a(18) =1a(19) =2a(20) =7a(21) =0a(22) =1a(23) =26a(24) =121a(25) =0a(26) =7a(27) =2a(28) =1a(29) =0