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 A062568 #18 Mar 01 2022 20:28:19 %S A062568 2047,15841,104653,1004653,10323769,100463443,1002261781,10000321321, %T A062568 100004790097,1000002977551,10000130243671,100002236680837, %U A062568 1000003918690669,10000008250001701,100000150553089531,1000000274500018837,10000003599249373469 %N A062568 a(n) is the smallest n-digit strong pseudoprime (in base 2). %H A062568 Patrick De Geest, <a href="http://www.worldofnumbers.com/won125.htm">Smallest n-digit pseudoprimes (base 2)</a> %H A062568 <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a> %e A062568 a(1)=2047 because 2047 is the smallest 4-digit strong pseudoprime to base 2. %Y A062568 Cf. A001567, A068216, A067845, A001262, A062852. %K A062568 hard,base,nonn %O A062568 4,1 %A A062568 _Shyam Sunder Gupta_, Feb 13 2002 %E A062568 Edited by _Charles R Greathouse IV_, Nov 01 2009 %E A062568 a(17)-a(20) from _Charles R Greathouse IV_, Mar 14 2011