Expansion of e.g.f. 1 / ( 1 - Sum_{k>=0} x^(4*k+3) / (4*k+3)! ).

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =0a(5) =0a(6) =20a(7) =1a(8) =0a(9) =1680a(10) =240a(11) =1a(12) =369600a(13) =102960a(14) =4160a(15) =168168001a(16) =76876800a(17) =7743840a(18) =137225153280a(19) =93117024001a(20) =17091609600