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 1-4 of 4 results.

A237811 Primes p such that 2*p+1 and 2*p+9 are also prime.

Original entry on oeis.org

2, 5, 11, 29, 131, 179, 239, 281, 359, 491, 641, 659, 719, 761, 809, 911, 1229, 1439, 1481, 1811, 2549, 2699, 2819, 3299, 3449, 3491, 4211, 4349, 4481, 5051, 5279, 5441, 5639, 5741, 6101, 6269, 6449, 6581, 6899, 7121, 7211, 7541, 7649, 7691, 8111, 8741, 8951
Offset: 1

Views

Author

Colin Barker, Feb 13 2014

Keywords

Examples

			11 is in the sequence because 11, 2*11+1 = 23 and 2*11+9 = 31 are all prime.

Links

Crossrefs

Cf. A126107, A237810, A237812, A237813, A237814.

Programs

  • Magma
    [p: p in PrimesUpTo(9200) | IsPrime(2*p+1) and IsPrime(2*p+9)]; // Vincenzo Librandi, Feb 15 2014
  • Mathematica
    Select[Prime[Range[10000]], PrimeQ[2 # + 1]&&PrimeQ[2 # + 9]&] (* Vincenzo Librandi, Feb 15 2014 *)
  • PARI
    s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+9), s=concat(s, p))); s

A237812 Primes p such that 2*p+1 and 2*p+13 are also prime.

Original entry on oeis.org

2, 3, 5, 23, 29, 83, 89, 113, 173, 233, 239, 293, 509, 653, 719, 743, 1013, 1049, 1223, 1289, 1499, 2003, 2039, 2063, 2129, 2339, 2393, 2459, 2543, 2693, 2753, 2819, 2963, 3389, 3449, 4409, 4733, 4919, 5039, 6053, 6113, 6263, 6323, 6329, 6449, 7433, 7643
Offset: 1

Views

Author

Colin Barker, Feb 13 2014

Keywords

Examples

			23 is in the sequence because 23, 2*23+1 = 47 and 2*23+13 = 59 are all prime.

Links

Crossrefs

Cf. A126107, A237810, A237811, A237813, A237814.

Programs

  • Magma
    [p: p in PrimesUpTo(9200) | IsPrime(2*p+1) and IsPrime(2*p+13)]; // Vincenzo Librandi, Feb 15 2014
  • Mathematica
    Select[Prime[Range[10000]], PrimeQ[2 # + 1] && PrimeQ[2 # + 13] &] (* Vincenzo Librandi, Feb 15 2014 *)
Select[Prime[Range[1000]],AllTrue[2#+{1,13},PrimeQ]&] (* Harvey P. Dale, Jun 27 2023 *)
  • PARI
    s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+13), s=concat(s, p))); s

A237813 Primes p such that 2*p+1 and 2*p+15 are also prime.

Original entry on oeis.org

2, 11, 23, 29, 41, 83, 89, 113, 131, 179, 191, 281, 293, 359, 419, 431, 491, 509, 593, 641, 653, 683, 719, 1019, 1049, 1103, 1229, 1289, 1409, 1451, 1511, 1583, 1601, 1811, 1889, 1931, 2003, 2039, 2069, 2129, 2141, 2273, 2393, 2399, 2459, 2543, 2549, 2699
Offset: 1

Views

Author

Colin Barker, Feb 13 2014

Keywords

Examples

			11 is in the sequence because 11, 2*11+1 = 23 and 2*11+15 = 37 are all prime.

Links

Crossrefs

Cf. A126107, A237810, A237811, A237812, A237814.

Programs

  • Magma
    [p: p in PrimesUpTo(4000) | IsPrime(2*p+1) and IsPrime(2*p+15)]; // Vincenzo Librandi, Feb 15 2014
  • Mathematica
    Select[Prime[Range[5000]], PrimeQ[2 # + 1] && PrimeQ[2 # + 15] &] (* Vincenzo Librandi, Feb 15 2014 *)
  • PARI
    s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+15), s=concat(s, p))); s

A237814 Primes p such that 2*p+1 and 2*p+19 are also prime.

Original entry on oeis.org

2, 5, 11, 41, 89, 131, 191, 251, 419, 431, 641, 809, 1031, 1229, 1409, 1439, 1511, 1559, 1601, 1889, 1901, 1931, 2069, 2351, 2399, 2459, 2699, 2741, 2819, 2939, 3359, 3449, 3491, 3761, 3779, 3911, 4409, 4919, 5081, 5849, 6131, 6449, 6491, 6551, 7079, 7151
Offset: 1

Views

Author

Colin Barker, Feb 13 2014

Keywords

Examples

			11 is in the sequence because 11, 2*11+1 = 23 and 2*11+19 = 41 are all prime.

Links

Crossrefs

Cf. A126107, A237810, A237811, A237812, A237813.

Programs

  • Magma
    [p: p in PrimesUpTo(8000) | IsPrime(2*p+1) and IsPrime(2*p+19)]; // Vincenzo Librandi, Feb 15 2014
  • Mathematica
    Select[Prime[Range[8000]], PrimeQ[2 # + 1] && PrimeQ[2 # + 19] &] (* Vincenzo Librandi, Feb 15 2014 *)
  • PARI
    s=[]; forprime(p=2, 10000, if(isprime(2*p+1) && isprime(2*p+19), s=concat(s, p))); s
Showing 1-4 of 4 results.

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

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