cp's OEIS Frontend

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.

A175236 Primes p such that 2^p+23 is also prime.

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%I A175236 #17 Apr 07 2025 15:16:35
%S A175236 3,7,79,359,1031,1039,11311,47599
%N A175236 Primes p such that 2^p+23 is also prime.
%C A175236 a(9) > 5*10^5. - _Robert Price_, Sep 18 2015
%F A175236 A057203 INTERSECT A000040. [_R. J. Mathar_, Jul 06 2010]
%e A175236 For p=3, 2^3+23=31; p=7, 2^7+23=131; p=79, 2^79+23=604462909807314587353111
%t A175236 Select[Prime[Range[1000]], PrimeQ[2^#+23]&] (*_Robert Price_, Sep 18 2015 *)
%o A175236 (Magma) [p: p in PrimesUpTo(1000) | IsPrime(2^p+23) ];
%K A175236 nonn,more
%O A175236 1,1
%A A175236 _Vincenzo Librandi_, Mar 09 2010
%E A175236 a(5)-a(6) from _R. J. Mathar_, Jul 06 2010
%E A175236 a(7)-a(8) from _Robert Price_, Sep 18 2015