Expansion of e.g.f.: tan(x)*(1+x).

Terms

a(0) =0a(1) =1a(2) =2a(3) =2a(4) =8a(5) =16a(6) =96a(7) =272a(8) =2176a(9) =7936a(10) =79360a(11) =353792a(12) =4245504a(13) =22368256a(14) =313155584a(15) =1903757312a(16) =30460116992a(17) =209865342976