A338729 - OEIS

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A338729

a(n) = number of permutations avoiding the simsum pattern 213 and the classical pattern 321.

1, 1, 2, 4, 8, 18, 45, 119

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..7.

Marilena Barnabei, Flavio Bonetti, Niccolò Castronuovo, Matteo Silimbani, Permutations avoiding a simsun pattern, The Electronic Journal of Combinatorics (2020) Vol. 27, Issue 3, P3.45. See Section 4.3.

CROSSREFS

Sequence in context: A125809 A245176 A000117 * A308030 A252653 A006771

Adjacent sequences: A338726 A338727 A338728 * A338730 A338731 A338732

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Dec 01 2020.

STATUS

approved