a(n) = Sum_{k=0..n} 3^k * binomial(n,k) * binomial(3*n,k).
A387930
a(n) = Sum_{k=0..n} 3^k * binomial(n,k) * binomial(3*n,k).
Terms
- a(0) =1a(1) =10a(2) =172a(3) =3322a(4) =67564a(5) =1415080a(6) =30204820a(7) =653318956a(8) =14270008636a(9) =314044486264
External references
- oeis: A387930