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 A059762 Initial primes of Cunningham chains of first type with length exactly 3. Primes in A059453 which survive as primes just two "2p+1 iterations", forming chains of exactly 3 terms. 17
 41, 1031, 1451, 1481, 1511, 1811, 1889, 1901, 1931, 3449, 3491, 3821, 3911, 5081, 5441, 5849, 6101, 6131, 7151, 7349, 7901, 8969, 9221, 10691, 10709, 11171, 11471, 11801, 12101, 12821, 12959, 13229, 14009, 14249, 14321, 14669, 14741, 15161 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Chris Caldwell's Prime Glossary, Cunningham chains. Warut Roonguthai, Yves Gallot's Proth.exe and Cunningham Chains. Eric Weisstein's World of Mathematics, Cunningham Chain. FORMULA {(p-1)/2, p, 2p+1, 4p+3, 8p+7} = {composite, prime, prime, prime, composite} EXAMPLE 41 is here because 20 and 325 are composites,41,83,167 are primes. MATHEMATICA ipccQ[n_]:=Module[{c=(n-1)/2}, PrimeQ[NestList[2#+1&, c, 4]]=={False, True, True, True, False}]; Select[Prime[Range[2000]], ipccQ] (* Harvey P. Dale, Nov 10 2014 *) CROSSREFS Cf. A023272, A023302, A023330, A005384, A005385, A059452-A059455, A007700. Sequence in context: A038397 A104349 A091314 * A069362 A016093 A130639 Adjacent sequences:  A059759 A059760 A059761 * A059763 A059764 A059765 KEYWORD nonn AUTHOR Labos Elemer, Feb 20 2001 EXTENSIONS Definition corrected by Alexandre Wajnberg, Aug 31 2005 STATUS approved

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Last modified April 14 06:30 EDT 2021. Contains 342946 sequences. (Running on oeis4.)