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 A004227 #10 Dec 07 2019 02:59:33 %S A004227 0,302,478,603,699,779,846,904,955,1000,1042,1080,1114,1147,1177,1205, %T A004227 1231,1256,1279,1302,1323,1343,1362,1381,1398,1415,1432,1448,1463, %U A004227 1478,1492,1506,1519,1532,1545 %N A004227 a(n) = ceiling(1000*log_10(n)). %t A004227 Ceiling[1000*Log10[Range[40]]] (* _Harvey P. Dale_, Jul 19 2018 *) %K A004227 nonn %O A004227 1,2 %A A004227 _N. J. A. Sloane_