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 A237017 #27 May 12 2025 20:19:32 %S A237017 359,1069199,1392269,2614169,10528649,16981379,18287309,19463519, %T A237017 21071489,21171509,22121579,24857639,40887569,41809259,76130129, %U A237017 88362479,118136279,128893049,131612609,153318449,289743689,315495539 %N A237017 Primes which start a Cunningham chain of length 4 where every entity of the chain is smallest of the prime number pair (p, p+8). %C A237017 a(n) generates a Cunningham chain of length 4 and a_n(i) + 8 is also prime for i = 1,2,3 and 4. %C A237017 This sequence is infinite under Dickson's conjecture. %H A237017 Chris K. Caldwell, <a href="https://t5k.org/glossary/xpage/CunninghamChain.html">Cunningham chain</a> %e A237017 a(1)=359, with associated Cunningham chain 359, 719, 1439, 2879; all of which are the lower member of a pair (p, p+8): (359,367), (719,727), (1439,1447), (2879,2887). %o A237017 (Python) %o A237017 from sympy import isprime, primerange %o A237017 is_a237017 = lambda p: all(isprime(q) for q in (p+8, 2*p+1, 2*p+9, 4*p+3, 4*p+11, 8*p+7, 8*p+15)) %o A237017 print(*[p for p in primerange(10**7) if is_a237017(p)], sep=', ') %o A237017 # _David Radcliffe_, May 11 2025 %Y A237017 Cf. A236443, A178421, A005602, A059763. %K A237017 nonn %O A237017 1,1 %A A237017 _Abhiram R Devesh_, Feb 02 2014