A137669 Prime numbers p such that p +- a and p +- b are prime numbers where a and b are distinct positive integers with a < b < p.

11, 13, 17, 23, 29, 31, 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

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..500

Example

71+-12=primes and 71+-18=primes
103+- 6=primes and 103+-24=primes
107+- 6=primes and 107+-24=primes
127+-24=primes and 127+-30=primes

Mathematica

l = {}; For[n = 1, n < 80, n++, c = 0; For[a = 1, a < Prime[n] - 2, a++, If[PrimeQ[Prime[n] - a] && PrimeQ[Prime[n] + a], For[b = a + 1, b < Prime[n], b++, If[PrimeQ[Prime[n] - b] && PrimeQ[Prime[n] + b], c = 1; Break; Break]]]]; If[c == 1, AppendTo[l, Prime[n]]]]; l (* Stefan Steinerberger, May 02 2008 *)

Crossrefs

Sequence in context: A120168 A260715 A087681 * A360979 A152470 A191023

Adjacent sequences: A137666 A137667 A137668 * A137670 A137671 A137672

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, Apr 27 2008

Extensions

Corrected and extended by Stefan Steinerberger, May 02 2008

Status

approved