Expansion of e.g.f. 2*x/(exp(-2*x)+exp(x)).

Terms

a(0) =0a(1) =1a(2) =1a(3) =-6a(4) =-13a(5) =110a(6) =363a(7) =-4214a(8) =-18581a(9) =276678a(10) =1525355a(11) =-27753022a(12) =-183611829a(13) =3948004606a(14) =30473073547a(15) =-756031185030