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 A240097 #5 Apr 01 2014 07:07:50 %S A240097 2,11,13,22,26,29,37,41,43,58,59,71,73,74,82,86,89,97,101,103,118,121, %T A240097 127,131,142,146,149,157,163,169,178,179,191,193,194,202,206,239,242, %U A240097 251,254,262,269,281,298,307,313,314,326,337,338,358,359,373,382 %N A240097 Numbers with primitive root -15. %H A240097 Vincenzo Librandi, <a href="/A240097/b240097.txt">Table of n, a(n) for n = 1..1000</a> %t A240097 pr = -15; Select[Range[2, 500], MultiplicativeOrder[pr, #] == EulerPhi[#] &] %Y A240097 Cf. numbers with positive primitive root r: A167791 (r=2), A167792 (r=3), A167793 (r=5), A167794 (r=6), A167795 (r=7), A167796 (r=8), A167797 (r=10), A240028 (r=11), A240030 (r=12), A240032 (r=13), A240094 (r=14), A240096 (r=15). %Y A240097 Cf. numbers with negative primitive root r: A167798 (r=-2), A167799 (r=-3), A167800 (r=-4), A167801 (r=-5), A167802 (r=-6), A167803 (r=-7), A167804 (r=-8), A167805 (r=-9), A167806 (r=-10), A240029 (r=-11), A240031 (r=-12), A240093 (r=-13), A240095 (r=-14). %K A240097 nonn,easy %O A240097 1,1 %A A240097 _Vincenzo Librandi_, Apr 01 2014