A163948 The number of functions on a finite set that are obtainable by a composition power (excluding identity as power).
1, 4, 21, 172, 1725, 21066, 307111
Offset: 1
Formula
a(n) = n^n - A163947(n).
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.
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