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.

A023298 Primes that remain prime through 3 iterations of function f(x) = 9x + 8.

Original entry on oeis.org

11, 61, 251, 397, 467, 727, 907, 1747, 1901, 2221, 2617, 3121, 3527, 3581, 4001, 4099, 4211, 4759, 5231, 5717, 6277, 6661, 6689, 7237, 7877, 8117, 8171, 8581, 9371, 9587, 11171, 12457, 12539, 13109, 14221, 15187, 15731, 16069, 16477, 16979, 17117, 17491
Offset: 1

Views

Author

David W. Wilson

Keywords

Comments

Primes p such that 9*p+8, 81*p+80, and 729*p+728 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

Crossrefs

Subsequence of A023235 and A023267.

Programs

  • Magma
    [n: n in [1..450000] | IsPrime(n) and IsPrime(9*n+8) and IsPrime(81*n+80) and IsPrime(729*n+728)]; // Vincenzo Librandi, Aug 04 2010

A023326 Primes that remain prime through 4 iterations of the function f(x) = 9x + 8.

Original entry on oeis.org

397, 467, 907, 1747, 1901, 4099, 7237, 8117, 8581, 9371, 9587, 23539, 28081, 32611, 36899, 41729, 54767, 55207, 57601, 61991, 64997, 66449, 73061, 74821, 75527, 86291, 115021, 118717, 125659, 126067, 134287, 140677, 147011, 148147, 151531, 171539
Offset: 1

Views

Author

David W. Wilson

Keywords

Comments

Primes p such that 9*p+8, 81*p+80, 729*p+728 and 6561*p+6560 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

Crossrefs

Subsequence of A023235, A023267, and A023298.

Programs

  • Magma
    [n: n in [1..5000000] | IsPrime(n) and IsPrime(9*n+8) and IsPrime(81*n+80) and IsPrime(729*n+728) and IsPrime(6561*n+6560)] // Vincenzo Librandi, Aug 04 2010
  • Mathematica
    Select[Prime[Range[16000]],AllTrue[Rest[NestList[9#+8&,#,4]],PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jun 25 2017 *)

A023354 Primes that remain prime through 5 iterations of function f(x) = 9x + 8.

Original entry on oeis.org

4099, 8117, 9587, 36899, 73061, 75527, 214771, 240197, 350219, 385709, 453199, 483649, 501029, 556607, 575119, 616991, 701497, 724597, 880067, 961069, 1230311, 1342501, 1376197, 1558811, 1566847, 1613707, 2450779, 2483711, 2536379, 2598157
Offset: 1

Views

Author

David W. Wilson

Keywords

Comments

Primes p such that 9*p+8, 81*p+80, 729*p+728, 6561*p+6560 and 59049*p+59048 are also primes. - Vincenzo Librandi, Aug 05 2010

Links

Crossrefs

Subsequence of A023235, A023267, A023298, and A023326.

Programs

  • Magma
    [n: n in [1..19000000] | IsPrime(n) and IsPrime(9*n+8) and IsPrime(81*n+80) and IsPrime(729*n+728) and IsPrime(6561*n+6560) and IsPrime(59049*n+59048)] // Vincenzo Librandi, Aug 05 2010
Showing 1-3 of 3 results.

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

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