A027288 a(n) = Sum_{k=0..floor(n/2)} T(n,k) * T(n,k+1), with T given by A026009.

1, 4, 12, 46, 145, 552, 1820, 6918, 23562, 89645, 312664, 1191885, 4232345, 16170728, 58229100, 222997812, 811985790, 3116622123, 11451785640, 44047806725, 163072988442, 628465576101, 2341484487832, 9040083756276, 33863310322100, 130957152428622

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Crossrefs

Sequence in context: A188312 A006735 A166115 * A149370 A149371 A149372

Adjacent sequences: A027285 A027286 A027287 * A027289 A027290 A027291

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 26 2019

Status

approved