a(n) = Sum_{k=0..floor(n/2)} (binomial(n,k) * binomial(n-k,k))^3.

A382842

a(n) = Sum_{k=0..floor(n/2)} (binomial(n,k) * binomial(n-k,k))^3.

Terms

    a(0) =1a(1) =1a(2) =9a(3) =217a(4) =1945a(5) =35001a(6) =764001a(7) =12079089a(8) =250222617a(9) =5424133465a(10) =107360983009

External references