a(n) = Sum_{k=0..n} binomial(4*n+4*k,n-k).
A390410
a(n) = Sum_{k=0..n} binomial(4*n+4*k,n-k).
Terms
- a(0) =1a(1) =5a(2) =41a(3) =361a(4) =3265a(5) =29939a(6) =276801a(7) =2573039a(8) =24008649a(9) =224642600a(10) =2106342663a(11) =19782332254a(12) =186034461253
External references
- oeis: A390410