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

A245104

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

Terms

    a(0) =1a(1) =6a(2) =136a(3) =23526a(4) =45511576a(5) =865387222026

External references