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 A364829 #14 Aug 12 2023 00:41:01 %S A364829 0,0,1,2,1,6,1,6,4,8,1,24,1,10,13,14,1,28,1,32,15,14,1,64,6,16,13,38, %T A364829 1,84,1,30,19,20,21,104,1,22,21,88,1,102,1,50,57,26,1,148,8,54,25,56, %U A364829 1,98,25,106,27,32,1,300,1,34,69,62,27,134,1,68,31,144 %N A364829 a(n) is the number of regions inside a regular n-gon after inscribing (always starting from the same point), for each proper divisor d_i of n greater than 1, a regular d_i-gon. %C A364829 Inspired by an X (or Twitter) post by Matt Henderson (see links section). %C A364829 This is A364828 without the outer circle. %H A364829 Matt Henderson, <a href="https://twitter.com/matthen2/status/1639925895254224898">X post</a>, 2023. %H A364829 Paolo Xausa, <a href="/A364829/a364829.pdf">Illustration of first terms</a>. %H A364829 Paolo Xausa, <a href="/A364829/a364829_1.pdf">Illustration of a(60)</a>. %F A364829 a(n) = 1, if n is prime. %F A364829 a(n) = n - 2, if n > 1 is a power of 2. %F A364829 a(n) = A364828(n) - n. %Y A364829 Cf. A006600, A007678, A364828, A364830, A364838. %K A364829 nonn %O A364829 1,4 %A A364829 _Paolo Xausa_, Aug 09 2023