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 A209193 #15 Dec 22 2024 12:21:35 %S A209193 23,47,59,83,167,839,2099,5879,6719,23099,27299,180179,414959,420419, %T A209193 628319,660659,840839,1141139,1681679,2042039,2277659,4084079,5525519, %U A209193 5705699 %N A209193 Safe primes that are also highly cototient numbers. %H A209193 PrimeFan, <a href="http://primefan.tripod.com/EsotericIntegerSequences.html">Listing of Esoteric Integer Sequences</a> %H A209193 PrimeFan, <a href="/A031214/a031214.pdf">Esoteric Integer Sequences</a> [Cached copy] %Y A209193 A005385 intersect A100827. %K A209193 nonn,more %O A209193 1,1 %A A209193 _N. J. A. Sloane_, Mar 05 2012 %E A209193 a(19)-a(24) calculated from the b-file at A100827 by _Amiram Eldar_, Apr 09 2020