a(n) = Sum_{k=0..n} (-1)^k * binomial(4*n-k+4,n-k).
A390592
a(n) = Sum_{k=0..n} (-1)^k * binomial(4*n-k+4,n-k).
Terms
- a(0) =1a(1) =7a(2) =56a(3) =468a(4) =4013a(5) =34998a(6) =308914a(7) =2751280a(8) =24675260a(9) =222540723a(10) =2016212292a(11) =18336279440a(12) =167293939222
External references
- oeis: A390592