Expansion of e.g.f. sinh(2 * log(1+x)) / 2.

Terms

a(0) =0a(1) =1a(2) =-1a(3) =6a(4) =-30a(5) =180a(6) =-1260a(7) =10080a(8) =-90720a(9) =907200a(10) =-9979200a(11) =119750400a(12) =-1556755200a(13) =21794572800a(14) =-326918592000