cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A117107 Number of permutations in S_n avoiding 21{bar 3}54 (i.e., every occurrence of 2154 is contained in an occurrence of a 21354) and such that the graph corresponding to the permutation is connected (see "Forest-like permutations" below).

Table of values

n a(n)
1 1
2 1
3 3
4 12
5 57
6 304
7 1765
8 10943
9 71519
10 488186
11 3456526
12 25251479
13 189545179

List of values

[1, 1, 3, 12, 57, 304, 1765, 10943, 71519, 488186, 3456526, 25251479, 189545179]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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