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.

A059323 Smaller term of closest safe prime pairs.

Original entry on oeis.org

11, 47, 167, 347, 467, 1307, 2027, 2447, 4127, 4787, 5087, 5387, 5927, 12527, 12647, 15287, 18947, 28307, 39107, 39827, 41507, 44687, 51827, 63587, 64007, 71987, 73847, 76367, 76907, 78467, 79967, 83207, 118787, 121547, 143687, 164987
Offset: 1

Views

Author

Labos Elemer, Jan 26 2001

Keywords

Examples

			11 and 23 are consecutive safe primes but not consecutive primes; 467 and 479 are consecutive safe primes and consecutive primes as well. Both 11 and 467 are here.
		

Crossrefs

Programs

  • Magma
    [p:p in PrimesUpTo(165000)| IsPrime(p+12) and IsPrime((p-1) div 2) and IsPrime( (p+11) div 2)]; // Marius A. Burtea, Jan 13 2020
  • Mathematica
    seqQ[n_] := And @@ PrimeQ[{n, n+12, (n-1)/2, (n+11)/2}]; Select[Range[165000], seqQ] (* Amiram Eldar, Jan 13 2020 *)

Formula

{x| both x and x+12 are safe primes}; Intersection(12+A005385, primes)

Extensions

Offset corrected by Amiram Eldar, Jan 13 2020