a(n) = S1(n,4), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).
A089661
a(n) = S1(n,4), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).
Terms
- a(0) =0a(1) =2a(2) =67a(3) =764a(4) =5492a(5) =30304a(6) =140672a(7) =577920a(8) =2167680a(9) =7577088a(10) =25037056a(11) =79016960a(12) =240028672a(13) =705961984a(14) =2019713024a(15) =5641535488a(16) =15431565312a(17) =41438281728a(18) =109462880256a(19) =284942925824a(20) =732004876288
External references
- oeis: A089661