A027258 a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A025177.

0, 6, 52, 428, 3552, 29790, 251980, 2145822, 18373296, 158025186, 1364247180, 11815188000, 102606325136, 893175905778, 7791151047204, 68086757974300, 595980599148672, 5224392846601730, 45857525238248604, 402997448078904948, 3545390129177031520, 31221592914677352138

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Crossrefs

Sequence in context: A083301 A334978 A005948 * A084773 A357154 A365194

Adjacent sequences: A027255 A027256 A027257 * A027259 A027260 A027261

Keyword

nonn

Author

Clark Kimberling

Extensions

a(1) corrected and more terms from Sean A. Irvine, Oct 26 2019

Status

approved