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 A046466 #21 Apr 10 2021 16:59:34 %S A046466 28,30,42,44,46,69,72,82,84,86,93,109,116 %N A046466 Numbers k such that the concatenation of numbers from 1 to k is the product of 7 primes (not necessarily distinct). %H A046466 Patrick De Geest, <a href="http://www.worldofnumbers.com/factorlist.htm">Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n</a> %H A046466 M. Fleuren, <a href="http://www.gallup.unm.edu/~smarandache/micha.txt">Smarandache Factors and Reverse factors</a> %H A046466 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_008.htm">Puzzle 8. Primes by Listing</a>, The Prime Puzzles & Problems Connection. %t A046466 Select[Range[100], PrimeOmega@FromDigits@Flatten@IntegerDigits@Range@# == 7 &] (* _Robert Price_, Oct 11 2019 *) %Y A046466 Cf. A046460. %K A046466 nonn,base,hard,more %O A046466 1,1 %A A046466 _Patrick De Geest_, Aug 15 1998 %E A046466 a(6)-a(13) from _Sean A. Irvine_, Apr 10 2021