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 A337018 #15 Dec 05 2020 04:34:45 %S A337018 1,6,6,18,18,6,18,18,18,54,54,30,54,42,6,18,18,18,54,54,30,54,42,18, %T A337018 54,54,54,162,162,90,162,126,30,90,90,66,162,150,78,126,90,6,18,18,18, %U A337018 54,54,30,54,42,18,54,54,54,162,162,90,162,126,30,90,90,66,162 %N A337018 a(n) is the number of hexagons at distance n from the central hexagon of a hexaflake. %C A337018 For symmetry reasons, a(n) is a multiple of 6 for any n > 0. %H A337018 Rémy Sigrist, <a href="/A337018/b337018.txt">Table of n, a(n) for n = 0..3281</a> %H A337018 Rémy Sigrist, <a href="/A337018/a337018.png">Illustration of initial terms</a> %H A337018 Rémy Sigrist, <a href="/A337018/a337018.gp.txt">PARI program for A337018</a> %H A337018 Wikipedia, <a href="https://en.wikipedia.org/wiki/N-flake#Hexaflake">Hexaflake</a> %F A337018 a(n) = 6 iff n belongs to A007051. %o A337018 (PARI) See Links section. %Y A337018 Cf. A337132 (Vicsek fractal analog), A337545 (pentaflake analog), A339124 (golden square fractal analog). %Y A337018 Cf. A007051. %K A337018 nonn %O A337018 0,2 %A A337018 _Rémy Sigrist_, Nov 21 2020