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.

A264451 Number of permutations of [n] with exactly two (possibly overlapping) occurrences of the generalized pattern 12-3.

Table of values

n a(n)
4 1
5 13
6 112
7 843
8 6089
9 43887
10 321357
11 2411686
12 18631631
13 148490575
14 1221894598
15 10382648734
16 91073271181
17 824221683639
18 7690752545310
19 73932347642395
20 731636916804531
21 7447376286108705
22 77913394499688645
23 837113596053971008
24 9229808681562243113

List of values

[1, 13, 112, 843, 6089, 43887, 321357, 2411686, 18631631, 148490575, 1221894598, 10382648734, 91073271181, 824221683639, 7690752545310, 73932347642395, 731636916804531, 7447376286108705, 77913394499688645, 837113596053971008, 9229808681562243113]

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

Content is available under The OEIS End-User License Agreement.