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Primes of a Generalized Cunningham chain of length 9 by the function f(p) = 2 * p + 13.
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%I #4 Jun 28 2013 01:11:44

%S 3467,6947,13907,27827,55667,111347,222707,445427,890867

%N Primes of a Generalized Cunningham chain of length 9 by the function f(p) = 2 * p + 13.

%C See comments and references of A176223 and A176247

%C Chain of 8 primes: 2, 17, 47, 107, 227, 467, 947, 1907

%C It is conjectured that arbitrarily long such chains exist

%D Joe Buhler: Algorithmic Number Theory: Third International Symposium, ANTS-III, New York: Springer, 1998

%D David J. Darling: The Universal Book of Mathematics: From Abracadabra to Zeno's Paradoxes, Hoboken: John Wiley & Sons, 2004

%D Paulo Ribenboim: Die Welt der Primzahlen. Geheimnisse und Rekorde, Springer-Verlag GmbH & Co. KG, 2006

%e 3467 = prime(486), (3467 - 13)/ 2 = 1727 = 11 * 157 is composite

%e f(3467) = 6947 = prime(891), f(6947) = 13907 = prime(1644)

%e f(13907) = 27827 = prime(3040), f( 27827) = 55667 = prime(5649)

%e f(55667) = 111347 = prime(10565), f(111347) = 222707 = prime(19832)

%e f(222707) = 445427 = prime(37374), f(445427) = 890867 = prime(70612)

%e f(890867) = 1781747 = 11 * 161977

%e 3467 is smallest prime for such a chain of 9 primes

%Y A000040, A005602, A005603, A176247

%K fini,nonn

%O 1,1

%A Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Apr 13 2010