Constant term in the expansion of (Sum_{k=0..n} k*(x^k + x^(-k)))^5.

Terms

a(0) =0a(1) =0a(2) =560a(3) =14240a(4) =146680a(5) =922680a(6) =4226040a(7) =15492680a(8) =48144680a(9) =131678360a(10) =325322360a(11) =739761880a(12) =1570082800a(13) =3143824320a(14) =5988841040a(15) =10926565040a(16) =19197225520a(17) =32624627920a(18) =53829216160a(19) =86499340720a(20) =135731931720a(21) =208455129960a(22) =313946860040a(23) =464464838200