a(n) = Sum_{k=0..n} binomial(4*n+k+2,n-k).
A390335
a(n) = Sum_{k=0..n} binomial(4*n+k+2,n-k).
Terms
- a(0) =1a(1) =7a(2) =57a(3) =486a(4) =4241a(5) =37540a(6) =335556a(7) =3020993a(8) =27348189a(9) =248663695a(10) =2269092254a(11) =20767746644a(12) =190557813508
External references
- oeis: A390335