a(n) = Sum_{k=0..n} 3^k * binomial(n,k) * binomial(3*n+1,k).
A388049
a(n) = Sum_{k=0..n} 3^k * binomial(n,k) * binomial(3*n+1,k).
Terms
- a(0) =1a(1) =13a(2) =232a(3) =4546a(4) =93172a(5) =1960765a(6) =41988880a(7) =910349716a(8) =19919778316a(9) =438996550852
External references
- oeis: A388049