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 A364828 #16 Aug 12 2023 00:40:13 %S A364828 1,2,4,6,6,12,8,14,13,18,12,36,14,24,28,30,18,46,20,52,36,36,24,88,31, %T A364828 42,40,66,30,114,32,62,52,54,56,140,38,60,60,128,42,144,44,94,102,72, %U A364828 48,196,57,104,76,108,54,152,80,162,84,90,60,360,62,96,132,126 %N A364828 a(n) is the number of regions inside a circle after inscribing (always starting from the same point), for each divisor d_i of n greater than 1, a regular d_i-gon. %C A364828 Inspired by an X (or Twitter) post by Matt Henderson (see links section). %H A364828 Matt Henderson, <a href="https://twitter.com/matthen2/status/1639925895254224898">X post</a>, 2023. %H A364828 Paolo Xausa, <a href="/A364828/a364828.pdf">Illustration of first terms</a>. %H A364828 Paolo Xausa, <a href="/A364828/a364828_1.pdf">Illustration of a(60)</a>. %F A364828 a(n) = n + 1, if n is prime. %F A364828 a(n) = 2*(n-1), if n > 1 is a power of 2. %F A364828 a(n) = A364829(n) + n. %Y A364828 Cf. A006600, A006533, A364829, A364830, A364838. %K A364828 nonn %O A364828 1,2 %A A364828 _Paolo Xausa_, Aug 09 2023