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 A140140 #8 Jan 11 2019 09:58:12
%S A140140 1,2,3,5,4,7,9,11,14,10,18,12,21,23,26,29,17,33,35,28,39,41,42,48,50,
%T A140140 51,53,45,43,63,46,68,69,74,38,78,66,83,86,89,90,95,59,98,85,49,111,
%U A140140 113,97,88,119,71,125,128,131,134,135,138,93,141,146,109,155,84,158,165,145
%N A140140 Positions of first appearances of odd primes in A137576.
%C A140140 a(n) <= (p_n-1)/2, where p_n is the n-th odd prime (A065091).
%t A140140 terms = 100;
%t A140140 a137576[n_] := Module[{t}, (t = MultiplicativeOrder[2, 2 n + 1])* DivisorSum[2 n + 1, EulerPhi[#]/MultiplicativeOrder[2, #] &] - t + 1];
%t A140140 A137576 = Array[a137576, 3 terms];
%t A140140 FirstPosition[A137576, #][[1]]& /@ Prime[Range[2, terms+1]] (* _Jean-François Alcover_, Jan 11 2019 *)
%Y A140140 Cf. A137576, A065091.
%K A140140 nonn
%O A140140 1,2
%A A140140 _Vladimir Shevelev_, May 10 2008
%E A140140 Corrected and extended by _Ray Chandler_, May 19 2008