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.

A126780 Number of functions f:{1,2,...,n}->{1,2,...,n} such that Im(f) contains 4 fixed elements.

Table of values

n a(n)
4 24
5 360
6 5880
7 109200
8 2298744
9 54313560
10 1425878520
11 41215616640
12 1301388272184
13 44580423767880
14 1647012735721080
15 65286028105225200
16 2764048499876532984
17 124490422185142171320
18 5943580498312544073720

List of values

[24, 360, 5880, 109200, 2298744, 54313560, 1425878520, 41215616640, 1301388272184, 44580423767880, 1647012735721080, 65286028105225200, 2764048499876532984, 124490422185142171320, 5943580498312544073720]

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

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