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.

A213079 Primes p such that 2p^2-1, 3p^2-2 and 4p^2-3 are also prime.

Original entry on oeis.org

409, 941, 6299, 10459, 11131, 11551, 15581, 16831, 17321, 17569, 25771, 25969, 26701, 31511, 36131, 40529, 43781, 50231, 52879, 54631, 54779, 56711, 60271, 61331, 70321, 71081, 83101, 83299, 85931, 100649, 110681, 116381, 118409, 118751, 120641, 130469
Offset: 1

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Author

Zak Seidov, Jun 04 2012

Keywords

Comments

Subsequence of A213078:
a(1) = 409 = A213078(4) = A106483(29) = A000040(80),
a(2) = 941 = A213078(7) = A106483(50) = A000040(160).

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(140000) | IsPrime(2*p^2-1) and IsPrime(3*p^2-2) and IsPrime(4*p^2-3)]; // Vincenzo Librandi, Apr 08 2013
  • Mathematica
    Select[Prime[Range[20000]], PrimeQ[2 #^2 - 1] && PrimeQ[3 #^2 - 2] && PrimeQ[4 #^2 - 3] &] (* T. D. Noe, Jun 06 2012 *)
    Select[Prime[Range[12500]],AllTrue[{2#^2-1,3#^2-2,4#^2-3},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 11 2015 *)