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 A338480 #6 Feb 16 2025 08:34:00 %S A338480 1,2,3,4,5,6,1,2,3,4,5,6,7,2,3,4,5,1,2,3,3,4,5,6,2,3,4,4,5,6,7,3,4,1, %T A338480 2,2,3,4,4,5,2,3,3,4,5,5,6,3,4,4,5,2,3,3,1,2,3,4,3,4,4,2,3,4,5,4,5,2, %U A338480 3,3,4,4,2,3,3,4,4,5,5,3,1,2,3,4,5,3,4,2,2,3,3,4,4,5,3,3,4,4,2,3,4 %N A338480 Least number of heptagonal numbers needed to represent n. %H A338480 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HeptagonalNumber.html">Heptagonal Number</a> %H A338480 <a href="/index/Pol#polygonal_numbers">Index to sequences related to polygonal numbers</a> %Y A338480 Cf. A000566, A002828, A061336, A100878, A338479, A338481. %K A338480 nonn %O A338480 1,2 %A A338480 _Ilya Gutkovskiy_, Oct 29 2020