a(n) = (1/(5*n+2)) * Sum_{k=0..n} (5*k+2) * binomial(5*n+2,n-k).
A390777
a(n) = (1/(5*n+2)) * Sum_{k=0..n} (5*k+2) * binomial(5*n+2,n-k).
Terms
- a(0) =1a(1) =3a(2) =19a(3) =149a(4) =1299a(5) =12074a(6) =117177a(7) =1173192a(8) =12026691a(9) =125592785a(10) =1331268654a(11) =14285866638a(12) =154890312081
External references
- oeis: A390777