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 A272766 #12 Jan 27 2017 19:07:05
%S A272766 2,3,4,6,7,10,15,19,22,30,31,34,36,51,52,54,70,75,90,91,96,99,100,106,
%T A272766 114,115,120,135,136,156,174,190,199,210,231,244,271,286,300,316,330,
%U A272766 346,351,370,376,394,411,414,415,430,439,496,510,516,520,531,546,559,576,615
%N A272766 Numbers n such that A281363(n) = n-1.
%C A272766 Conjecture: primorial numbers (A002110) are terms of this sequence.
%t A272766 Table[SelectFirst[Range[10^5], PowerMod[2^#, 2 n, 4 n^2 - 1] == 1 &] /. k_ /; k != n - 1 -> Nothing, {n, 620}] + 1 (* Version 10.2, or *)
%t A272766 Rest@ Union@ Table[If[# == n - 1, #, 0] &@ Block[{m = 1}, While[PowerMod[2^m, 2 n, 4 n^2 - 1] != 1, m++]; m], {n, 620}] + 1 (* _Michael De Vlieger_, May 06 2016, after _Giovanni Resta_ at A281363 *)
%Y A272766 Cf. A002110, A281363.
%K A272766 nonn,easy
%O A272766 1,1
%A A272766 _Juri-Stepan Gerasimov_, May 06 2016