A234280 Number of 231-avoiding extensions of comb K_{s,3}^{alpha}.

1, 8, 91, 1210, 17606

Offset

1,2

Comments

No formula is presently known.

Links

Table of n, a(n) for n=1..5.

Sophia Yakoubov, Pattern avoidance in extensions of comb-like posets, Journal of Combinatorics, Vol. 6, No. 1-2 (2015), pp. 249-272; arXiv preprint, arXiv:1310.2979 [math.CO], 2013-2014.

Crossrefs

Sequence in context: A190943 A180912 A378694 * A298013 A302614 A220573

Adjacent sequences: A234277 A234278 A234279 * A234281 A234282 A234283

Keyword

nonn,more

Author

N. J. A. Sloane, Dec 28 2013

Extensions

a(5) added by Amiram Eldar, May 06 2024

Status

approved