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 A171873 #4 Jun 02 2025 02:23:13 %S A171873 1,1,2,10,280,1173468 %N A171873 Column sums of triangle A171871. %C A171873 Next term is known to be greater than 220146725295227, based on link between A171871 and A039754. %H A171873 R. Munafo, <a href="http://mrob.com/pub/math/seq-a005646.html">Classifications of N Elements</a> %K A171873 nonn %O A171873 0,3 %A A171873 _Robert Munafo_, Jan 21 2010