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 A046465 #19 Apr 10 2021 16:59:27 %S A046465 11,12,18,19,22,24,32,33,39,49,57,65,70,71,75,76,78,79,81,83,85,87,88, %T A046465 91,95,96,99,105,110 %N A046465 Numbers k such that the concatenation of numbers from 1 to k is the product of 6 primes (not necessarily distinct). %H A046465 Patrick De Geest, <a href="http://www.worldofnumbers.com/factorlist.htm">Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n</a> %H A046465 M. Fleuren, <a href="http://www.gallup.unm.edu/~smarandache/micha.txt">Smarandache Factors and Reverse factors</a> %H A046465 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_008.htm">Puzzle 8. Primes by Listing</a>, The Prime Puzzles & Problems Connection. %t A046465 Select[Range[100], PrimeOmega@FromDigits@Flatten@IntegerDigits@Range@# == 6 &] (* _Robert Price_, Oct 11 2019 *) %Y A046465 Cf. A046460. %K A046465 nonn,base,hard,more %O A046465 1,1 %A A046465 _Patrick De Geest_, Aug 15 1998 %E A046465 a(12)-a(29) from _Sean A. Irvine_, Apr 10 2021