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A278583
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Numbers k such that k+1 is a prime, k+2 is twice a prime, and k+3 is three times a prime.
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5
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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
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OFFSET
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1,1
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COMMENTS
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REFERENCES
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R. K. Guy, Posting to Number Theory Mailing List, Nov 30 2016
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LINKS
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MATHEMATICA
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Select[Range[12, 25000, 12], AllTrue[{#+1, (#+2)/2, (#+3)/3}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 26 2020 *)
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PROG
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(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
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CROSSREFS
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Positions of terms >= 3 in A278500.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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