a(n) = Sum_{k=0..n} 5^k * 3^(n-k) * binomial(3*n+k-1,k).
A386765
a(n) = Sum_{k=0..n} 5^k * 3^(n-k) * binomial(3*n+k-1,k).
Terms
- a(0) =1a(1) =18a(2) =624a(3) =24432a(4) =1008876a(5) =42927318a(6) =1862060124a(7) =81862383432
External references
- oeis: A386765