a(n) = S2(n,3), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.
A089666
a(n) = S2(n,3), 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) =137a(3) =2136a(4) =23452a(5) =209840a(6) =1640346a(7) =11648224a(8) =76976048a(9) =481048128a(10) =2874897670a(11) =16564931504a(12) =92584313112a(13) =504313834336
External references
- oeis: A089666