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 A138539 #19 Jul 15 2018 13:33:59
%S A138539 2,3,5,7,13,17,19,37,41,43,61,73,89,97,101,109,113,157,163,181,193,
%T A138539 233,241,257,277,281,313,337,349,353,397,401,409,421,433,449,457,461,
%U A138539 487,521,541,577,593,601,613,617,641,661,673,701,733,757,761,769,821,829
%N A138539 Primes p_n for which A140141(n) < 2p_n, where p_n = n-th prime (A000040).
%C A138539 Apparently this is the union of {2} and A058341. - _R. J. Mathar_, Jul 03 2009
%C A138539 This sequence is the complement of A058340. - _Torlach Rush_, Jun 29 2018
%Y A138539 Cf. A140141, A039649, A000010, A000040, A058340.
%K A138539 nonn
%O A138539 1,1
%A A138539 _Vladimir Shevelev_, May 10 2008
%E A138539 Corrected and extended by _Ray Chandler_, May 20 2008