a(n) = Sum_{k=0..n} 4^(n-k) * binomial(n,k) * binomial(n+2,k).
A388412
a(n) = Sum_{k=0..n} 4^(n-k) * binomial(n,k) * binomial(n+2,k).
Terms
- a(0) =1a(1) =7a(2) =54a(3) =434a(4) =3567a(5) =29745a(6) =250620a(7) =2128180a(8) =18182829a(9) =156121067a(10) =1345960658a(11) =11643663366a(12) =101021276347a(13) =878673361077
External references
- oeis: A388412