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.

A080635 Number of permutations on n letters without double falls and without initial falls.

Table of values

n a(n)
0 1
1 1
2 1
3 3
4 9
5 39
6 189
7 1107
8 7281
9 54351
10 448821
11 4085883
12 40533129
13 435847959
14 5045745069
15 62594829027
16 828229153761
17 11644113200031
18 173331882039141
19 2723549731505163
20 45047085512477049
21 782326996336904679
22 14233537708408467549
23 270733989894887810547

List of values

[1, 1, 1, 3, 9, 39, 189, 1107, 7281, 54351, 448821, 4085883, 40533129, 435847959, 5045745069, 62594829027, 828229153761, 11644113200031, 173331882039141, 2723549731505163, 45047085512477049, 782326996336904679, 14233537708408467549, 270733989894887810547]

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

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