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 A256571 #30 Aug 26 2024 20:14:46 %S A256571 1,6,21,56,131,281,556,1046,1896,3346,5796,9916,16806,28316,47506, %T A256571 79476,132706 %N A256571 a(n) is the total number of pentagrams in a variant of pentagram fractal after n iterations. %C A256571 Inspired by A255870. But at the higher iterations, the perimeter is an irregular polygon instead of a pentagon. The construction rule is sides to vertices expansion. See illustration in the links. %H A256571 <a href="/A256571/b256571.txt">Table of n, a(n) for n = 1..17</a> %H A256571 Kival Ngaokrajang, <a href="/A256571/a256571.pdf">Illustration of initial terms</a> %Y A256571 Cf. A255870, A256429, A256569. %K A256571 nonn,more %O A256571 1,2 %A A256571 _Kival Ngaokrajang_, Apr 02 2015 %E A256571 a(9) corrected and a(10)-a(15) added by _Udo Vieth_, Jan 16 2023 %E A256571 a(16)-a(17) added by _Udo Vieth_, Aug 19 2024