Expansion of e.g.f. x + sqrt(x^2 + 1).

Terms

a(0) =1a(1) =1a(2) =1a(3) =0a(4) =-3a(5) =0a(6) =45a(7) =0a(8) =-1575a(9) =0a(10) =99225a(11) =0a(12) =-9823275a(13) =0a(14) =1404728325a(15) =0a(16) =-273922023375a(17) =0a(19) =0a(21) =0a(23) =0a(25) =0a(27) =0a(29) =0