A026997 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026703.

1, 6, 35, 168, 926, 4294, 23224, 106690, 571926, 2617886, 13965688, 63815684, 339452265, 1549699466, 8228066295, 37543939462, 199095075169, 908167940082, 4812012405883, 21945589904716, 116213845733553, 529936445158768, 2805163046954295, 12790521159853090, 67685654170211481

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Crossrefs

Sequence in context: A375248 A030532 A333800 * A014337 A002041 A103995

Adjacent sequences: A026994 A026995 A026996 * A026998 A026999 A027000

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 21 2019

Status

approved