A279201 Number of Wilf-equivalence classes of square permutations of 2n things that avoid 123.

1, 2, 12, 118, 1218, 14272

Offset

0,2

Links

Table of n, a(n) for n=0..5.

Samuele Giraudo, S. Vialette, Unshuffling Permutations, arXiv preprint arXiv:1601.05962 [cs.DS], 2016.

Crossrefs

Cf. A279200, A279202, A279203.

Sequence in context: A012628 A012623 A009742 * A121425 A132692 A009546

Adjacent sequences: A279198 A279199 A279200 * A279202 A279203 A279204

Keyword

nonn,more

Author

N. J. A. Sloane, Dec 15 2016

Status

approved