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A137877
Numbers k such that 18*k - 1 and 18*k + 1 are twin primes.
5
1, 4, 6, 10, 11, 15, 24, 29, 45, 46, 49, 59, 64, 71, 90, 104, 111, 116, 119, 126, 130, 144, 155, 165, 176, 181, 185, 196, 199, 204, 214, 225, 231, 235, 241, 249, 251, 266, 274, 276, 279, 301, 314, 319, 325, 326, 350, 364, 365, 370, 386, 396, 406, 416, 420, 431
OFFSET
1,2
LINKS
EXAMPLE
1 is in the sequence since 18*1 - 1 = 17 and 18*1 + 1 = 19 are twin primes.
MATHEMATICA
q=18; lst={}; Do[r=n*q; If[PrimeQ[r-1]&&PrimeQ[r+1], AppendTo[lst, n]], {n, 1, 10^3}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 07 2008 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 19 2008
STATUS
approved