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 A278583 Numbers k such that k+1 is a prime, k+2 is twice a prime, and k+3 is three times a prime. 5
 12, 36, 156, 540, 876, 1200, 1380, 1620, 2016, 2556, 2856, 3060, 4356, 4440, 5076, 5580, 5700, 6336, 6636, 6660, 6996, 7416, 8220, 9180, 9660, 9900, 10836, 11496, 12456, 12600, 12720, 12756, 13680, 14436, 15240, 16920, 17076, 18216, 18300, 18396, 19440, 21000, 21576, 22620, 23556, 24480 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are divisible by 12. - Daniel Poveda Parrilla, Dec 12 2016 REFERENCES R. K. Guy, Posting to Number Theory Mailing List, Nov 30 2016 LINKS Antti Karttunen and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 563 terms from Antti Karttunen) PROG (PARI) list(lim)=my(v=List()); forprime(p=2, lim+1, if(p%6==1 && isprime(p\2+1) && isprime(p\3+1), listput(v, p-1))); Vec(v) \\ Charles R Greathouse IV, Dec 03 2016 CROSSREFS Equals A036570(n) - 1. Positions of terms >= 3 in A278500. Cf. A074200. Sequence in context: A064518 A238923 A135178 * A216381 A085331 A225100 Adjacent sequences:  A278580 A278581 A278582 * A278584 A278585 A278586 KEYWORD nonn AUTHOR N. J. A. Sloane, Nov 30 2016 STATUS approved

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Last modified April 24 04:23 EDT 2019. Contains 322406 sequences. (Running on oeis4.)