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A263298
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Numbers n such that n-23, n-1, n+1 and n+23 are consecutive primes.
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1
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19890, 43890, 157770, 400680, 436650, 609780, 681090, 797310, 924360, 978180, 1093200, 1116570, 1179150, 1185930, 1313700, 1573110, 1663350, 2001510, 2110290, 2163570, 2336310, 2372370, 2408280, 2415630, 2562690, 2877840, 2896740, 2961900
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OFFSET
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1,1
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COMMENTS
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n-23 and n+1 belong to A242476 (p and p+22 are primes).
n-23 and n-1 belong to A033560 (p and p+24 are primes).
(End)
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LINKS
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EXAMPLE
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19890 is the average of the four consecutive primes 19867, 19889, 19891, 19913.
43890 is the average of the four consecutive primes 43867, 43889, 43891, 43913.
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MATHEMATICA
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{p, q, r, s} = {2, 3, 5, 7}; lst={}; While[p<5000000, If[Differences[{p, q, r, s}]=={22, 2, 22}, AppendTo[lst, q + 1]]; {p, q, r, s}={q, r, s, NextPrime@s}]; lst (* Vincenzo Librandi, Oct 14 2015 *)
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PROG
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(Python)
from sympy import isprime, prevprime, nextprime
for i in range(0, 5000001, 6):
..if isprime(i-1) and isprime(i+1) and prevprime(i-1) == i-23 and nextprime(i+1) == i+23: print (i, end=', ')
(PARI) isok(n) = isprime(n-1) && isprime(n+1) && (precprime(n-2) == n-23) && (nextprime(n+2) == n+23); \\ Michel Marcus, Oct 14 2015
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CROSSREFS
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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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