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 A192764 #15 Aug 26 2024 11:42:31 %S A192764 1,2,6,14,66,86,230,2006,3876,3920,5418,8820,11900,16669,19446,28243, %T A192764 33408,37919,40595 %N A192764 Numbers k such that 2^(k-1)+2*k-1 is a prime number. %C A192764 a(20) > 10^5 if it exists. - _Michael S. Branicky_, Aug 26 2024 %t A192764 Select[Range[4000], PrimeQ[2^(# - 1) + 2# - 1] &] (* _Alonso del Arte_, Jul 09 2011 *) %o A192764 (PARI) for(n=1,10^6,if(ispseudoprime(2^(n-1)+2*n-1),print1(n,", "))); %Y A192764 Cf. A004051, A163115, A176691, A192436. %K A192764 nonn,more %O A192764 1,2 %A A192764 _Juri-Stepan Gerasimov_, Jul 09 2011 %E A192764 a(13)-a(19) from _Michael S. Branicky_, Jul 14 2023