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 A338491 #7 Feb 16 2025 08:34:00 %S A338491 1,2,3,4,5,1,2,3,4,5,6,2,3,4,5,1,2,3,4,5,6,2,3,4,5,6,7,3,4,5,1,2,3,4, %T A338491 5,6,2,3,4,5,6,7,3,4,5,6,2,3,4,5,1,2,3,4,5,6,2,3,4,5,6,2,3,4,5,6,2,3, %U A338491 4,5,6,7,3,4,5,1,2,3,4,5,6,2,3,4,5,6,7,3,4,5,6,2,3,4,5,6,7,3,4,5,6 %N A338491 Least number of centered pentagonal numbers needed to represent n. %H A338491 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPentagonalNumber.html">Centered Pentagonal Number</a> %H A338491 <a href="/index/Ce#CENTRALCUBE">Index entries for sequences related to centered polygonal numbers</a> %Y A338491 Cf. A005891, A100878, A101412, A234533, A338482, A338484, A338492, A338494. %K A338491 nonn %O A338491 1,2 %A A338491 _Ilya Gutkovskiy_, Oct 30 2020