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.

A216224 Natural growth of an aliquot sequence driven by a perfect number 2^(p-1)*((2^p)-1), but starting at 27.

Original entry on oeis.org

27, 53, 55, 89, 91, 133, 187, 245, 439, 441, 1041, 1743, 3633, 7503, 13329, 25203, 44429, 66547, 76813, 90803, 90805, 167243, 187957, 280907, 332005, 499739, 499741, 600995, 841405, 1177979, 1392181, 1977419, 1992661, 2398187, 3062293, 3600363, 6739253, 7507147
Offset: 1

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Author

Michel Marcus, Mar 13 2013

Keywords

Comments

Quote from the abstract of the article by te Riele: "In this note, the existence of an aliquot sequence with more than 5092 monotonically increasing even terms is proved". The author uses the perfect number corresponding to the Mersenne prime 2^p-1 with p=19937 (whereas the script below only uses p=521).

Crossrefs

Programs

  • PARI
    lista(p=521, nb) = {perf = 2^(p-1)*(2^p-1); a = 27*perf; print1(a/perf, ", "); for (i=1, nb, a = sigma(a) - a; print1(a/perf, ", "); if (gcd(a/perf, p) != 1, return()););} \\ Michel Marcus, Mar 13 2013