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 1-2 of 2 results.

A237267 The positions of records in A236747.

Original entry on oeis.org

1, 2, 5, 105, 585, 1041, 1590, 3582, 5460, 19425, 21450, 21540, 33495, 42315, 101745, 122265, 151710, 176190, 252525, 267435, 318780, 343800, 464100, 542640, 868140, 996765, 1080450, 1217370, 1322685, 1461495, 1477875, 1601985, 2523675, 2792790, 3512145
Offset: 1

Views

Author

Antti Karttunen and Juri-Stepan Gerasimov, Feb 05 2014

Keywords

Comments

Smallest k such that A236747(k) = n: 1, 2, 5, 105, 585, 1041, 1590, 3582, 6870, 5460,...
Smallest prime p such that A236747(p) = n: 2, 5, 593, 1889, 4457,...

Crossrefs

Cf. A236747 (number of 0 <= k <= sqrt(n) such that n-k and n+k are both prime).

Extensions

a(7)-a(9) from Michel Marcus, Feb 05 2014.
a(9)-a(35) from Giovanni Resta, Feb 09 2014

A236917 Numbers n for which there is no k such that n - k and n + k are both prime, with 0 <= k <= sqrt(n).

Original entry on oeis.org

1, 8, 22, 24, 25, 28, 32, 35, 38, 46, 49, 51, 52, 55, 58, 62, 68, 74, 80, 82, 85, 87, 91, 94, 112, 114, 115, 116, 119, 121, 123, 124, 125, 126, 128, 130, 136, 142, 146, 152, 155, 164, 166, 175, 178, 184, 200, 203, 206, 207, 208, 209, 212, 214, 215, 216, 218
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Feb 01 2014

Keywords

Comments

Numbers n such that A236747(n) = 0.
Probably finite. Perhaps a(4565) = 2591107 is the last term; any other terms are greater than 10^9. - Charles R Greathouse IV, Feb 03 2014

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Showing 1-2 of 2 results.

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