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 A103804 Primes p such that both 2p +/- 21 are primes. 2
 13, 19, 29, 31, 41, 59, 79, 89, 101, 109, 131, 179, 211, 239, 241, 271, 311, 331, 349, 409, 421, 449, 499, 509, 521, 541, 601, 619, 701, 751, 821, 839, 881, 1009, 1091, 1181, 1201, 1319, 1321, 1399, 1429, 1459, 1489, 1531, 1571, 1619, 1801, 1949, 1951 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA p, 2p-21 and 2p+21 all are positive primes. MATHEMATICA Select[Range[2000], PrimeQ[ # ] && PrimeQ[2# + 21] && PrimeQ[2# - 21] &] Select[Prime[Range[4, 500]], And@@PrimeQ[2#+{21, -21}]&] (* Harvey P. Dale, Dec 18 2012 *) CROSSREFS Cf. A103802, A103803. Sequence in context: A227092 A123840 A258589 * A063640 A092104 A281483 Adjacent sequences:  A103801 A103802 A103803 * A103805 A103806 A103807 KEYWORD nonn AUTHOR Zak Seidov, Feb 16 2005 STATUS approved

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Last modified May 9 21:52 EDT 2021. Contains 343746 sequences. (Running on oeis4.)