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A090832
Numbers n such that p(n), p(n)+6, p(n)+12, p(n)+18 are consecutive primes, where p(n) denotes n-th prime.
20
54, 271, 464, 682, 709, 821, 829, 1510, 1594, 1726, 1842, 1853, 2009, 2086, 2209, 2600, 2876, 3253, 3303, 5463, 5689, 6252, 6386, 7064, 7438, 7620, 7728, 7918, 8090, 8145, 8229, 8631, 8654, 8828, 9105, 9184, 9243, 9997, 10052, 10074, 10329, 10934
OFFSET
1,1
EXAMPLE
p(271)=1741: 1741,1747,1753,1759 are consecutive primes,1747=1741+6,1753=1741+12,1759=1741+18
MATHEMATICA
p[n_]:=Prime[n]; Select[Range[15000], p[ #+1]-p[ # ]==p[ #+2]-p[ #+1]==p[ #+3]-p[ #+2]==6&] - Zak Seidov, Mar 05 2006
PrimePi[#[[1]]]&/@Select[Partition[Prime[Range[11000]], 4, 1], Differences[#]=={6, 6, 6}&] (* Harvey P. Dale, Oct 28 2023 *)
KEYWORD
easy,nonn
AUTHOR
Pierre CAMI, Dec 09 2003
EXTENSIONS
Corrected and extended by Zak Seidov, Mar 05 2006
STATUS
approved