a(n) = Sum_{k = 0..n} binomial(n,k) * binomial(n+1,k+1) * 4^k.
A098665
a(n) = Sum_{k = 0..n} binomial(n,k) * binomial(n+1,k+1) * 4^k.
Terms
- a(0) =1a(1) =6a(2) =43a(3) =332a(4) =2661a(5) =21810a(6) =181455a(7) =1526040a(8) =12939145a(9) =110413406a(10) =947052723a(11) =8157680228a(12) =70518067309a(13) =611426078346
External references
- oeis: A098665