A027309 a(n) = Sum_{k=0..n+1} T(n,k) * T(n,k+1), with T given by A026323.

2, 16, 123, 956, 7519, 59742, 478869, 3868104, 31458348, 257396972, 2117494621, 17504651148, 145341743066, 1211584784416, 10136488835157, 85085339305360, 716366098507550, 6048143934750432, 51194316337883625, 434360166677159652, 3693446859517381827

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Crossrefs

Sequence in context: A341925 A229808 A301947 * A241466 A069868 A338186

Adjacent sequences: A027306 A027307 A027308 * A027310 A027311 A027312

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms and title corrected by Sean A. Irvine, Oct 27 2019

Status

approved