a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026670.
A026984
a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026670.
Terms
- a(0) =1a(1) =10a(2) =68a(3) =394a(4) =2011a(5) =10258a(6) =47327a(7) =229186a(8) =1007891a(9) =4752128a(10) =20351196a(11) =94455408a(12) =398021603a(13) =1828645056a(14) =7624936963a(15) =34786976248a(16) =144011195937a(17) =653694082256
External references
- oeis: A026984