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.

A137670 Prime numbers p such that p-b < p-a < p < p+a < p+b are prime for some a and b.

Original entry on oeis.org

17, 23, 29, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313
Offset: 1

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Author

Vladimir Joseph Stephan Orlovsky, Apr 27 2008; corrected May 02 2008

Keywords

Comments

It seems highly likely that all primes other than 2,3,5,7,19 are in this sequence. There are no further exceptions to 4 billion. - Charles R Greathouse IV, Apr 19 2010

Crossrefs

Cf. A071681.

Programs

  • Mathematica
    s=""; q=1; For[i=2, i<10^2, p=Prime[i]; For[a=2, aq&&PrimeQ[p-c]&&PrimeQ[p+c], (*Print[p, ":", a, ", ", b, ", ", c]; *)s=s<>ToString[p]<>", "; q=p]; c=c+2]]; b=b+2]]; a=a+2]; i++ ]; Print[s]

Extensions

New name from Charles R Greathouse IV, Apr 19 2010