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 A063847 #11 Oct 01 2019 09:47:48 %S A063847 15841,29341,52633,252601,314821,1909001,3581761,4335241,5049001, %T A063847 5310721,5444489,15247621,29111881,35703361,36765901,38624041, %U A063847 53711113,68154001,99036001,101649241,104852881,115039081,133800661,161035057,172290241,214852609,238244041,299736181 %N A063847 Carmichael numbers which are also base-2 strong pseudoprimes. %H A063847 Daniel Suteu, <a href="/A063847/b063847.txt">Table of n, a(n) for n = 1..10000</a> %Y A063847 Cf. A001262, A002997. %K A063847 nonn %O A063847 1,1 %A A063847 _Shyam Sunder Gupta_, Aug 26 2001 %E A063847 Corrected and extended by _Daniel Suteu_, Oct 01 2019