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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A345991 Smallest number of the form m*(m+1)*(m+2) that is divisible by n.

Original entry on oeis.org

6, 6, 6, 24, 60, 6, 210, 24, 504, 60, 990, 24, 1716, 210, 60, 336, 4080, 504, 5814, 60, 210, 990, 10626, 24, 13800, 1716, 17550, 336, 21924, 60, 26970, 3360, 990, 4080, 210, 504, 46620, 5814, 1716, 120, 63960, 210, 74046, 1320, 720, 10626, 97290, 336, 110544, 13800, 4080, 1716, 140556, 17550, 990
Offset: 1

Views

Author

N. J. A. Sloane, Jul 13 2021

Keywords

Comments

a(n) = m*(m+1)*(m+2) where m = A345990(n).

Crossrefs

Cf. A000292, A007571, A265647, A345989, A345990.

A133378 a(1)=1. For n >= 2, a(n) = the largest prime divisor of (a(n-1)^a(n-1) + 1).

Original entry on oeis.org

1, 2, 5, 521
Offset: 1

Views

Author

Leroy Quet, Oct 28 2007

Keywords

Comments

a(5) depends on the factorization of the 1408-digit composite number (521^521+1)/(2 * 3^2 * 29 * 375121); see factordb.com link. - Michael S. Branicky, Jan 27 2023

Links

Crossrefs

Cf. A007571.

Programs

  • Mathematica
    NestList[FactorInteger[#^#+1][[-1,1]]&,1,3] (* Harvey P. Dale, Jun 21 2012 *)
Previous Showing 11-12 of 12 results.

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

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