Expansion of e.g.f. tanh(x/(1 - x)).

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =0a(5) =-104a(6) =-1200a(7) =-10352a(8) =-68992a(9) =-177536a(10) =5310720a(11) =145374208a(12) =2512029696a(13) =33484862464a(14) =294806779904