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.

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A023350 Primes that remain prime through 5 iterations of function f(x) = 8x + 7.

Original entry on oeis.org

25589, 220469, 225629, 286619, 783269, 1215629, 1407389, 1542029, 1642919, 2329469, 2776979, 3104159, 4082759, 4229129, 5405999, 5905619, 6548849, 6862859, 7681409, 7904669, 8623799, 8971049, 9599309, 9658469, 9725039, 11420579
Offset: 1

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Author

David W. Wilson

Keywords

Comments

Primes p such that 8*p+7, 64*p+63, 512*p+511, 4096*p+4095 and 32768*p+32767 are also primes. - Vincenzo Librandi, Aug 05 2010

Links

Crossrefs

Subsequence of A023231, A023263, A023294, A023322, and A139487.

Programs

  • Magma
    [n: n in [1..19000000] | IsPrime(n) and IsPrime(8*n+7) and IsPrime(64*n+63) and IsPrime(512*n+511) and IsPrime(4096*n+4095) and IsPrime(32768*n+32767)]; // Vincenzo Librandi, Aug 05 2010
  • Mathematica
    i5Q[p_]:=AllTrue[Rest[NestList[8#+7&,p,5]],PrimeQ]; Select[Prime[Range[760000]],i5Q] (* Harvey P. Dale, Jul 05 2025 *)

Formula

a(n) == 29 (mod 30). - John Cerkan, Nov 08 2016
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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