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 A046468 #30 Apr 10 2021 16:59:46 %S A046468 26,36,40,52,74,90,102,112,114,115 %N A046468 Numbers k such that the concatenation of numbers from 1 to k is the product of 9 primes (not necessarily distinct). %H A046468 Patrick De Geest, <a href="http://www.worldofnumbers.com/factorlist.htm">Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n</a> %H A046468 M. Fleuren, <a href="http://www.gallup.unm.edu/~smarandache/michafleuren.htm">Factors and primes of Smarandache sequences</a>. %H A046468 M. Fleuren, <a href="http://www.gallup.unm.edu/~smarandache/micha.txt">Smarandache Factors and Reverse factors</a> %H A046468 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_008.htm">Puzzle 8. Primes by Listing</a>, The Prime Puzzles & Problems Connection. %t A046468 Select[Range[52],PrimeOmega[FromDigits[Flatten[IntegerDigits/@ Range[ #]]]] ==9&] (* _Harvey P. Dale_, Nov 12 2017 *) %Y A046468 Cf. A046460. %K A046468 nonn,base,hard,more,less %O A046468 1,1 %A A046468 _Patrick De Geest_, Aug 15 1998 %E A046468 a(5)-a(10) from _Sean A. Irvine_, Apr 10 2021