a(0) = 1; for n >= 1, a(n) = sum(binomial(n,k)^3*binomial(n+k,k+1)^2,k = 0..n)/n^2.

A074649

a(0) = 1; for n >= 1, a(n) = sum(binomial(n,k)^3*binomial(n+k,k+1)^2,k = 0..n)/n^2.

Terms

    a(0) =1a(1) =2a(2) =23a(3) =434a(4) =10897a(5) =327270a(6) =11076235a(7) =408850370a(8) =16119036965a(9) =669177449258

External references