E.g.f.: Sum_{n>=1} x^(n^2) * exp(2*x^n) / n!.

Terms

a(0) =1a(1) =4a(2) =12a(3) =44a(4) =80a(5) =912a(6) =448a(7) =41344a(8) =62784a(9) =2424320a(10) =11264a(11) =319358976a(12) =53248a(13) =11623886848a(14) =435891701760a(16) =1114112a(18) =4980736a(22) =96468992