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.

A126778 Number of functions f:{1,2,...,n}->{1,2,...,n} such that Im(f) contain two fixed elements.

Table of values

n a(n)
2 2
3 12
4 110
5 1320
6 19502
7 341796
8 6927230
9 159338640
10 4100173022
11 116692730220
12 3639243694814
13 123411407978040
14 4521172518708302
15 177943592279325684
16 7487880700093141502
17 335470576863324471840
18 15942605654030732807102
19 801021400634789561255868

List of values

[2, 12, 110, 1320, 19502, 341796, 6927230, 159338640, 4100173022, 116692730220, 3639243694814, 123411407978040, 4521172518708302, 177943592279325684, 7487880700093141502, 335470576863324471840, 15942605654030732807102, 801021400634789561255868]

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

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