A026977 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026659.

1, 4, 24, 90, 365, 1376, 7365, 28002, 121049, 465004, 2437089, 9396986, 41758527, 162167568, 842470494, 3277804402, 14798196587, 57865149612, 299015494394, 1170434872374, 5339682500573, 20979019813768, 107997589923134, 424558473013940, 1951503161793927, 7693926097133316

Offset

1,2

Links

Table of n, a(n) for n=1..26.

Crossrefs

Sequence in context: A212681 A026694 A026967 * A026952 A222670 A225681

Adjacent sequences: A026974 A026975 A026976 * A026978 A026979 A026980

Keyword

nonn

Author

Clark Kimberling

Extensions

More term from Sean A. Irvine, Oct 20 2019

Status

approved