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 A338492 #5 Feb 16 2025 08:34:00 %S A338492 1,2,3,4,5,6,7,1,2,3,4,5,6,7,8,2,3,4,5,6,7,1,2,3,4,5,6,7,8,2,3,4,5,6, %T A338492 7,8,9,3,4,5,6,7,1,2,3,4,5,6,7,8,2,3,4,5,6,7,8,9,3,4,5,6,7,8,2,3,4,5, %U A338492 6,7,1,2,3,4,5,6,7,8,2,3,4,5,6,7,8,2,3,4,5,6,7,8,2,3,4,5,6,7,8,9,3 %N A338492 Least number of centered heptagonal numbers needed to represent n. %H A338492 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPolygonalNumber.html">Centered Polygonal Numbers</a> %H A338492 <a href="/index/Ce#CENTRALCUBE">Index entries for sequences related to centered polygonal numbers</a> %Y A338492 Cf. A069099, A101412, A234533, A338480, A338482, A338484, A338491. %K A338492 nonn %O A338492 1,2 %A A338492 _Ilya Gutkovskiy_, Oct 30 2020