a(n) = S2(n,5), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

A089668

a(n) = S2(n,5), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

Terms

    a(0) =0a(1) =4a(2) =521a(3) =17136a(4) =320716a(5) =4356560a(6) =48024786a(7) =456843520a(8) =3893995184a(9) =30487086144a(10) =223052123830

External references