a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(4*n+1,k).
A388135
a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(4*n+1,k).
Terms
- a(0) =1a(1) =8a(2) =99a(3) =1366a(4) =19801a(5) =295272a(6) =4484869a(7) =69006672a(8) =1071995589a(9) =16776537520a(10) =264094891670
External references
- oeis: A388135