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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =-12a(5) =120a(6) =-1020a(7) =8820a(8) =-72828a(9) =505008a(10) =-1376160a(11) =-51546000a(12) =1698674208a(13) =-38050144704a(14) =739129595568