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 A228724 #23 Jan 19 2023 13:22:40 %S A228724 0,0,0,3,7,-23,-73,-57,186,2126,3161,3885,12731,39462,-13815,-151907, %T A228724 1117163,5045162,-19274680,18700047,127912738,252060543,-656184524, %U A228724 2799754423,5292148929,27646015077,49454963317,271968742992 %N A228724 Difference between pi(10^n) and A226945(n), where pi(x) is the number of primes <= x. %H A228724 Eduard Roure Perdices, <a href="/A228724/b228724.txt">Table of n, a(n) for n = 1..29</a> (terms n = 1..24 from Arkadiusz Wesolowski; terms n = 25,26 from David Baugh). %H A228724 Wikipedia, <a href="http://en.wikipedia.org/wiki/Prime_number_theorem">Prime number theorem</a> %F A228724 a(n) = A006880(n) - A226945(n). %Y A228724 Cf. A006880, A226945, A057794. %K A228724 sign %O A228724 1,4 %A A228724 _Arkadiusz Wesolowski_, Aug 31 2013 %E A228724 a(25)-a(26) added by _David Baugh_, Mar 17 2015 %E A228724 a(27)-a(28) added using A006880 and A226945, by _Eduard Roure Perdices_, Apr 16 2021