E.g.f.: exp( (x * exp(x) - sinh(x)) / 2 ).

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =5a(5) =12a(6) =58a(7) =220a(8) =1145a(9) =5684a(10) =33284a(11) =198412a(12) =1306355a(13) =8945046a(14) =65658392a(15) =503505600a(16) =4076565489a(17) =34442610648a(18) =304577372128