a(n) = Sum_{k=0..n} (k+1) * 2^k * 3^(n-k) * binomial(2*k,2*(n-k)).
A390849
a(n) = Sum_{k=0..n} (k+1) * 2^k * 3^(n-k) * binomial(2*k,2*(n-k)).
Terms
- a(0) =1a(1) =4a(2) =24a(3) =248a(4) =1628a(5) =11232a(6) =77632a(7) =513088a(8) =3372816a(9) =21936320a(10) =141137024a(11) =901877376a(12) =5725796800a(13) =36148870144a(14) =227148097536
External references
- oeis: A390849