a(n) = Sum_{k=0..n} binomial(4*n+4*k+1,n-k).
A390416
a(n) = Sum_{k=0..n} binomial(4*n+4*k+1,n-k).
Terms
- a(0) =1a(1) =6a(2) =50a(3) =444a(4) =4040a(5) =37219a(6) =345411a(7) =3220935a(8) =30134735a(9) =282618136a(10) =2655353228a(11) =24983716550a(12) =235330304876
External references
- oeis: A390416