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%I #12 Apr 03 2023 10:36:09
%S 89,63419,127139,405269,810809,1069199,1178609,1333889,1598699,
%T 1806089,1958249,2606069,2848949,3241289,3339989,3784199,3962039,
%U 4088879,4444829,4664249,4894889,4897709,5132999,5215499,5238179,6026309,6059519,6088529,6490769,6676259
%N Initial (unsafe) primes of Cunningham chains of first type with length exactly 6.
%C Special terms of A059453. Not identical to A023330 of which 1122659,2164229,2329469,.. etc. are omitted since have exact length 7 or larger. Unsafe primes starting complete chains of length 6.
%H Chris Caldwell's Prime Glossary, <a href="https://t5k.org/glossary/page.php?sort=CunninghamChain">Cunningham chains</a>.
%e 89 is here because (89-1)/2=44 and 64*89+63=5759=13*443 are composites, while 89,179,359,719,1439,2879 are primes. 1122659 is not here because initiates a chain of length 7.
%e 4658939 is not here because (4658939-1)/2 = 2329469 is prime. - _Sean A. Irvine_, Oct 09 2022
%Y Cf. A023272, A023302, A023330, A005384, A005385, A059452-A059455, A007700, A059759, A059760, A059761, A059762, A059763, A059764, A038397, A104349, A091314, A069362, A016093, A014937, A057326.
%Y Cf. A005602, A053176, A059500, A057331, A059688, A059690.
%K nonn
%O 1,1
%A _Labos Elemer_, Feb 21 2001
%E Entry revised by _N. J. A. Sloane_ Apr 01 2006
%E a(12) onward corrected and extended by _Sean A. Irvine_, Oct 09 2022
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