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.

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A376431 a(n) is the least odd prime factor of prime(n)^prime(n)-1.

Original entry on oeis.org

3, 13, 11, 3, 5, 3, 10949, 3, 11, 7, 3, 3, 5, 3, 23, 13, 29, 3, 3, 5, 3, 3, 41, 11, 3, 5, 3, 53, 3, 7, 3, 5, 17, 3, 37, 3, 3, 3, 83, 43, 89, 3, 5, 3, 7, 3, 3, 3, 113, 3, 29, 7, 3, 5, 21589, 131, 67, 3, 3, 5, 3, 73, 3, 5, 3, 79, 3, 3, 173, 3, 11, 179, 3, 3, 3, 191
Offset: 1

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Author

Hugo Pfoertner, Sep 27 2024

Keywords

Crossrefs

Programs

  • PARI
    a376431(n) = my(pp=prime(n)^prime(n)-1); forprime (p=3, oo, if(pp%p==0, return(p)))

Formula

a(n) = A078701(A088730(n)). - Michel Marcus, Sep 27 2024
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