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 A309855 #23 Jul 19 2025 15:27:57 %S A309855 7,151,379,547,631,727,769,1531,1627,1741,1789,1999,2131,2437,2659, %T A309855 2797,2857,2917,3217,3331,3511,3919,3931,4591,4651,4759,4801,4831, %U A309855 4957,5281,5689,5701,5779,5821,5881,6067,6217,6361,6619,6871,7039,7309,7489,7927,8179,8221,8329,8581,8641 %N A309855 Primes p such that 2*p^5-1 is also prime. %H A309855 Harvey P. Dale, <a href="/A309855/b309855.txt">Table of n, a(n) for n = 1..1000</a> %F A309855 A000040 INTERSECT A309854. %t A309855 Select[Range[10000], PrimeQ[#]&&PrimeQ[2*(#^5)-1] &] (* _Metin Sariyar_, Aug 21 2019 *) %t A309855 Select[Prime[Range[1100]],PrimeQ[2#^5-1]&] (* _Harvey P. Dale_, Jul 19 2025 *) %Y A309855 Cf. A182785 (2*p^4-1 prime), A177104 (2*p^3-1 prime), A309854 (2*n^5-1 prime). %K A309855 nonn %O A309855 1,1 %A A309855 _R. J. Mathar_, Aug 20 2019