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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.

A254139 a(n) = smallest composite c for which there exist exactly n bases b with b < c such that b^(c-1) == 1 (mod c), i.e., smallest composite c which is a Fermat pseudoprime to exactly n bases less than c.

Table of values

n a(n)
1 9
2 28
3 15
4 66
5 49
6 232
7 45
8 190
9 121
10 276
11 169
12 1106

List of values

[9, 28, 15, 66, 49, 232, 45, 190, 121, 276, 169, 1106]

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

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