G.f.: A(x) = Sum_{n>=0} (2*n+1) * 8^n * x^(n*(n+1)/2).

Terms

a(0) =1a(1) =24a(2) =0a(3) =320a(4) =0a(5) =0a(6) =3584a(7) =0a(8) =0a(9) =0a(10) =36864a(11) =0a(12) =0a(13) =0a(14) =0a(15) =360448a(16) =0a(17) =0a(18) =0a(19) =0a(20) =0a(21) =3407872a(22) =0a(23) =0a(24) =0a(25) =0a(26) =0a(27) =0a(28) =31457280a(29) =0