G.f.: (1+x^2)^2*(x^4-6*x^3+1)/(x^2-1)^4.

Terms

a(0) =1a(1) =0a(2) =6a(3) =-6a(4) =20a(5) =-36a(6) =50a(7) =-114a(8) =104a(9) =-264a(10) =190a(11) =-510a(12) =316a(13) =-876a(14) =490a(15) =-1386a(16) =720a(17) =-2064a(18) =1014a(19) =-2934a(20) =1380a(21) =-4020a(22) =1826a(23) =-5346a(24) =2360a(25) =-6936a(26) =2990a(27) =-8814a(28) =3724a(29) =-11004