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.

A287899 Number of permutations of [2n] with exactly n cycles such that the elements of each cycle form an integer interval.

Table of values

n a(n)
0 1
1 1
2 5
3 31
4 217
5 1661
6 13721
7 121703
8 1157857
9 11826121
10 129877645
11 1535504015
12 19546846441
13 267633414517
14 3932330905361
15 61806788736551
16 1035452546213441
17 18421374554192017
18 346790652640704725
19 6885640002624595007
20 143771244649798115257

List of values

[1, 1, 5, 31, 217, 1661, 13721, 121703, 1157857, 11826121, 129877645, 1535504015, 19546846441, 267633414517, 3932330905361, 61806788736551, 1035452546213441, 18421374554192017, 346790652640704725, 6885640002624595007, 143771244649798115257]

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

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