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A137724 Prime numbers p such that p +- ((p-1)/6) are primes. 1
37, 181, 397, 757, 829, 1657, 2089, 2161, 2341, 3061, 5077, 6337, 7057, 7309, 7561, 8389, 9109, 9829, 10369, 10729, 13789, 17137, 21061, 21817, 21961, 23869, 24517, 24877, 25237, 26209, 28297, 29269, 31177, 31249, 32077, 32257, 33049, 33301, 35281, 38377, 39709, 41221, 42337, 44641, 47161 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

37+-6 = primes,

181+-30 = primes,

397+-(396/6) = primes.

MATHEMATICA

w=6; s=""; For[i=1, i<10^3*2, p=Prime[i]; If[PrimeQ[p-((p-1)/w)]&&PrimeQ[p+((p-1)/w)], (*Print[p, ":", p-((p-1)/w), ", ", p+((p-1)/w)]; *)s=s<>ToString[p]<>", "]; i++ ]; Print[s]

Select[Prime[Range[50000]], PrimeQ[# + (# - 1) / 6]&& PrimeQ[# - (# - 1) / 6] &] (* Vincenzo Librandi, Jun 15 2013 °)

PROG

(MAGMA) [p: p in PrimesInInterval(5, 50000)| IsPrime((7*p-1) div 6 ) and IsPrime((5*p+1) div 6)]; // Vincenzo Librandi, Jun 15 2013

CROSSREFS

Sequence in context: A195546 A142410 A164940 * A172080 A142181 A107196

Adjacent sequences:  A137721 A137722 A137723 * A137725 A137726 A137727

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 27 2008

STATUS

approved

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Last modified June 18 17:46 EDT 2019. Contains 324215 sequences. (Running on oeis4.)