A137772 Prime numbers p such that p +- ((p-1)/30030) are primes.

5945941, 19819801, 23963941, 42342301, 42882841, 56756701, 74414341, 169369201

Offset

1,1

Comments

Note that 2*3*5*7*11*13 = 30030.

Links

Table of n, a(n) for n=1..8.

Example

5945941+5945940/30030 = 5946139 and 5945941-5945940/30030 = 5945743, which are primes.

Mathematica

w=30030; 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[10550000]], PrimeQ[# + (# - 1) / 30030] && PrimeQ[# - (# - 1) / 30030] &] (* Vincenzo Librandi, Jun 15 2013 *)

Prog

(Magma) [p: p in PrimesInInterval(5, 120000000)| IsPrime((30031*p-1) div 30030 ) and IsPrime((30029*p+1) div 30030)]; // Vincenzo Librandi, Jun 15 2013

Crossrefs

Sequence in context: A106809 A106810 A161008 * A205262 A183022 A183021

Adjacent sequences: A137769 A137770 A137771 * A137773 A137774 A137775

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Apr 27 2008, corrected May 10 2008

Extensions

More terms from Vincenzo Librandi, Jun 15 2013

Status

approved