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.

A317479 Primes with record values of corresponding Fortunate numbers (A005235).

Original entry on oeis.org

2, 3, 5, 7, 11, 23, 29, 31, 41, 47, 61, 79, 83, 101, 137, 193, 199, 337, 349, 557, 677, 977, 1069, 1087, 1279, 1483, 1579, 1877, 2053, 2591, 2713, 2843, 3359, 3823, 4243, 6011, 7393, 7411, 7459, 8179, 8389, 15313, 18287, 19463, 21323, 22153, 23011, 27067
Offset: 1

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Author

Amiram Eldar, Jul 29 2018

Keywords

Comments

The corresponding record values of the Fortunate numbers are 3, 5, 7, 13, 23, 37, 61, 67, 71, 107, 109, 151, 197, 233, 643, 751, 773, 883, 1381, 1423, 2087, 2243, 2357, 3559, 3739, 5323, 5689, 6271, 7187, 7309, 8713, 11069, 11411, 19699, 20249, 25621, 28351, 28817, 32443, 39769, 59981, 78059, 82339, 86293, 89657, 90127, 101021, 129589, ...
Primes that are in both of these 2 sequences: 3, 5, 7, 23, 61, ...

Examples

			23 is in the sequence since the prime next to 23#+1 is 23#+37 and 37 is larger than all the Fortunate numbers before it (3, 5, 7, 13, 23, 17, 19, 23).
		

Crossrefs

Cf. A005235.

Programs

  • Mathematica
    primorial[n_] := Times @@ Prime[Range[n]]; gap[n_] := NextPrime[n + 1] - n; fort[n_] := gap[primorial[n]]; fm=0; s={}; Do[f = fort[n]; If[f > fm, AppendTo[s, Prime[n]]; fm = f], {n, 1, 30}]; s