a(n) = S1(n,5), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).
A089662
a(n) = S1(n,5), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).
Terms
- a(0) =0a(1) =2a(2) =131a(3) =2172a(4) =20386a(5) =138580a(6) =763824a(7) =3631712a(8) =15470144a(9) =60527232a(10) =221297920a(11) =765580288a(12) =2529498624a(13) =8039103488a(14) =24713744384a(15) =73818562560a(16) =215011065856a(17) =612515381248
External references
- oeis: A089662