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.

Showing 1-3 of 3 results.

A200861 Prime factors of 10^100 - 1.

Original entry on oeis.org

3, 3, 11, 41, 101, 251, 271, 3541, 5051, 9091, 21401, 25601, 27961, 60101, 7019801, 182521213001, 14103673319201, 78875943472201, 1680588011350901
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 23 2011

Keywords

Comments

Is this sequence the same as "Primes p such that 10^p - 1 divides 10^(10^100) - 10"?

Links

Crossrefs

Subsequence of A178070 except for 3.

Programs

  • Maple
    sort(map(i-> i[1]$i[2], ifactors(10^100-1)[2]))[];  # Alois P. Heinz, Jan 27 2023
  • Mathematica
    Join[{3}, Transpose[FactorInteger[10^100 - 1]][[1]]]

Extensions

Name changed by T. D. Noe and Arkadiusz Wesolowski, Nov 29 2011

A227245 Numbers k such that 10^k - 1 divides 10^(10^(10^100)) - 10.

Original entry on oeis.org

1, 3, 9, 11, 17, 33, 41, 51, 73, 99, 101, 123, 137
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 02 2013

Keywords

Links

Crossrefs

Cf. A173394, A178070, A200879.

A216437 Primes which do not divide any Repunit R(10^n) = (10^(10^n)-1)/9.

Original entry on oeis.org

2, 3, 5, 7, 13, 19, 23, 29, 31, 37, 43, 47, 53, 59, 61, 67, 71, 79, 83, 89, 97, 103, 107, 109, 113, 127, 131, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 263, 269, 277, 281, 283, 293, 307, 311, 313, 317, 331
Offset: 1

Views

Author

V. Raman, Sep 07 2012

Keywords

Comments

The primes not in the sequence A178070.

Crossrefs

Cf. A178070.
Showing 1-3 of 3 results.

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

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