This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A059766 #19 Jul 15 2024 10:23:23 %S A059766 89,63419,127139,405269,810809,1069199,1178609,1333889,1598699, %T A059766 1806089,1958249,2606069,2848949,3241289,3339989,3784199,3962039, %U A059766 4088879,4444829,4664249,4894889,4897709,5132999,5215499,5238179,6026309,6059519,6088529,6490769,6676259 %N A059766 Initial (unsafe) primes of Cunningham chains of first type with length exactly 6. %C A059766 Special terms of A059453. Not identical to A023330 of which 1122659, 2164229, 2329469, ..., etc. are omitted since they have exact length 7 or larger. %C A059766 Unsafe primes starting complete chains of length 6. %H A059766 Amiram Eldar, <a href="/A059766/b059766.txt">Table of n, a(n) for n = 1..1000</a> %H A059766 Chris Caldwell's Prime Glossary, <a href="https://t5k.org/glossary/page.php?sort=CunninghamChain">Cunningham chains</a>. %e A059766 89 is a term because (89-1)/2 = 44 and 64*89+63 = 5759 = 13*443 are composites, while 89, 179, 359, 719, 1439, and 2879 are primes. %e A059766 1122659 is not a term because it initiates a chain of length 7. %e A059766 4658939 is not a term because (4658939-1)/2 = 2329469 is prime. - _Sean A. Irvine_, Oct 09 2022 %Y A059766 Cf. A023272, A023302, A023330, A005384, A005385, A059452, A059453, A059454, A059455, A007700, A059759, A059760, A059761, A059762, A059763, A059764, A038397, A104349, A091314, A069362, A016093, A014937, A057326. %Y A059766 Cf. A005602, A053176, A059500, A057331, A059688, A059690. %K A059766 nonn %O A059766 1,1 %A A059766 _Labos Elemer_, Feb 21 2001 %E A059766 Entry revised by _N. J. A. Sloane_ Apr 01 2006 %E A059766 a(12) onward corrected and extended by _Sean A. Irvine_, Oct 09 2022