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.

A249583 Number of permutations p of [n] such that p(i) > p(i+1) iff i == 2 (mod 3).

Table of values

n a(n)
0 1
1 1
2 1
3 2
4 5
5 9
6 40
7 169
8 477
9 3194
10 19241
11 74601
12 666160
13 5216485
14 25740261
15 287316122
16 2769073949
17 16591655817
18 222237912664
19 2543467934449
20 17929265150637
21 280180369563194
22 3712914075133121
23 30098784753112329
24 537546603651987424
25 8094884285992309261

List of values

[1, 1, 1, 2, 5, 9, 40, 169, 477, 3194, 19241, 74601, 666160, 5216485, 25740261, 287316122, 2769073949, 16591655817, 222237912664, 2543467934449, 17929265150637, 280180369563194, 3712914075133121, 30098784753112329, 537546603651987424, 8094884285992309261]