E.g.f.: Product_{k>=1} (1 + x^k)^(tan(x)/k).

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =36a(5) =-30a(6) =1384a(7) =-1680a(8) =95120a(9) =-269136a(10) =10673176a(11) =-39346560a(12) =1646512480a(13) =-9198926880a(14) =351447935136