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 A138067 #15 Jun 07 2021 01:15:16 %S A138067 2,2,3,0,2,5,0,2,105,0,2,11,0,5,3,0,2,15,0,2,9,0,2,113,0,5,7,0,2,27,0, %T A138067 3,3,0,3,3,0,12,61,0,2,3,0,4,255,0,8,63,0,2,9,0,2,3473,0,2,3,0,2,15,0, %U A138067 2,87,0,3,23,0,36,1861,0,4,3,0,2,5,0,3,7,0,136,425,0,11 %N A138067 Least k > 1 such that (2n-1)^k + 2 is prime, or 0 if no such number exists. %C A138067 a(3n+1) = 0 for n > 0. %C A138067 a(84) > 100000. - _Ray Chandler_, Aug 10 2011 %Y A138067 Cf. A084713 (smallest prime of the form (2n-1)^k + 2, or 0 if no such number exists). %Y A138067 Cf. A138066 (least k > 0 such that (2n-1)^k + 2 is prime, or 0 if no such number exists). %Y A138067 Cf. A051783 (k such that 3^k + 2 is prime). %Y A138067 Cf. A087885 (k such that 5^k + 2 is prime). %Y A138067 Cf. A090649, A109076, A113480, A138048, A138049, A138050, A138051, A087886, A113481. %K A138067 hard,nonn %O A138067 1,1 %A A138067 _Alexander Adamchuk_, Mar 02 2008 %E A138067 a(54)-a(83) from _Donovan Johnson_, Oct 29 2008