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 A138066 #12 Jun 06 2021 20:58:58 %S A138066 1,1,1,0,1,1,0,1,1,0,1,11,0,1,1,0,2,1,0,1,1,0,1,113,0,1,7,0,1,1,0,3,1, %T A138066 0,1,1,0,12,1,0,1,3,0,1,255,0,8,1,0,1,1,0,1,1,0,1,3,0,2,15,0,2,1,0,1, %U A138066 23,0,1,1,0,4,3,0,1,1,0,3,1,0,136,1,0,1 %N A138066 Least k > 0 such that (2n-1)^k + 2 is prime, or 0 if no such number exists. %C A138066 a(3n+1) = 0 for n > 0. %C A138066 a(84) > 100000. - _Ray Chandler_, Aug 10 2011 %Y A138066 Cf. A084713 (smallest prime of the form (2n-1)^k + 2, or 0 if no such number exists). %Y A138066 Cf. A138067 (least k > 1 such that (2n-1)^k + 2 is prime, or 0 if no such number exists). %Y A138066 Cf. A051783 (k such that 3^k + 2 is prime). %Y A138066 Cf. A087885 (k such that 5^k + 2 is prime). %Y A138066 Cf. A090649, A109076, A113480, A138048, A138049, A138050, A138051, A087886, A113481. %K A138066 hard,nonn %O A138066 1,12 %A A138066 _Alexander Adamchuk_, Mar 02 2008