A307346 Number of uniquely sorted permutations of [2n+1] that avoid the patterns 231 and 4123.

1, 1, 3, 10, 36, 138, 553, 2288, 9699, 41908

Offset

0,3

Links

Table of n, a(n) for n=0..9.

C. Defant, Catalan intervals and uniquely sorted permutations, arXiv:1904.02627 [math.CO], 2019.

Example

The 3 uniquely sorted permutations of [7] that avoid 231 and 4123 are 2164357, 2143657, and 4321567.

Crossrefs

Cf. A180874.

Sequence in context: A002212 A340941 A149041 * A202834 A129247 A162162

Adjacent sequences: A307343 A307344 A307345 * A307347 A307348 A307349

Keyword

nonn,more

Author

Colin Defant, Apr 03 2019

Status

approved