E.g.f.: 1/(1-sinh(x)-x).

Terms

a(0) =1a(1) =2a(2) =8a(3) =49a(4) =400a(5) =4081a(6) =49964a(7) =713665a(8) =11649936a(9) =213946513a(10) =4365604372a(11) =97988751433