a(n) = Sum_{k=0..n} binomial(n,k) * (2^k + 3^k)^(n-k) * 3^(k^2).
A245105
a(n) = Sum_{k=0..n} binomial(n,k) * (2^k + 3^k)^(n-k) * 3^(k^2).
Terms
- a(0) =1a(1) =5a(2) =115a(3) =23075a(4) =45885991a(5) =868409174855
External references
- oeis: A245105
A245105
a(n) = Sum_{k=0..n} binomial(n,k) * (2^k + 3^k)^(n-k) * 3^(k^2).