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 A048538 #13 Feb 16 2025 08:32:40 %S A048538 42,4422,46440,464442,44642442,144444342,40447444340,2344449414440, %T A048538 42794944444440,443448440044440,24442434644444460,455758444444444440, %U A048538 34444442714441644442,44441704844441444442,14444904404444444646450,344407444483444494444942,1244444414842444444444506 %N A048538 Smallest oblong (promic) number containing exactly n 4's. %H A048538 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PronicNumber.html">Pronic Number</a> %Y A048538 Cf. A048537, A002378. %Y A048538 Cf. A048530, A048532, A048534, A048536, A048540, A048542, A048544, A048546, A048548. %K A048538 nonn,base %O A048538 1,1 %A A048538 _Patrick De Geest_, May 15 1999 %E A048538 a(13)-a(17) from _Giovanni Resta_, Oct 09 2019