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 A225747 a(n) = smallest prime q > a(n-1) such that 2*prime(n)*q^prime(n)+1 is also prime. 1
 2, 3, 7, 17, 1579, 1997, 2347, 3323, 6637, 11161, 13829, 18287, 40759, 42197, 42337, 45757, 46141, 48383, 49253, 51631, 52541, 53549, 73477, 78079, 81677, 111439, 164363, 166567, 170441, 180667, 191507, 202729, 209029, 257351, 292471, 294809, 300569, 328787 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Pierre CAMI, Table of n, a(n) for n = 1..177 EXAMPLE 2*2*2^2+1=17 prime so a(1)=2, 2*3*2^3+1=49 composite, 2*3*3^3+1=163 prime so a(2)=3 as 3>2. PROG (PFGW & SCRIPTIFY) SCRIPT DIM n, 0 DIM k, 0 DIM q DIMS t OPENFILEOUT myfile, a(n).txt LABEL a SET n, n+1 IF n>177 THEN END LABEL b SET k, k+1 SET q, p(k) SETS t, %d\,; q PRP 2*p(n)*q^p(n)+1, t IF ISPRP THEN GOTO c GOTO b LABEL c WRITE myfile, q GOTO a CROSSREFS Cf. A225403. Sequence in context: A102226 A195530 A295509 * A058334 A303090 A131093 Adjacent sequences:  A225744 A225745 A225746 * A225748 A225749 A225750 KEYWORD nonn AUTHOR Pierre CAMI, May 14 2013 STATUS approved

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Last modified January 18 05:09 EST 2020. Contains 330995 sequences. (Running on oeis4.)