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 A240841 #12 Nov 09 2024 02:22:40
%S A240841 1,1,2,3,5,9,14,21,34,52,82,127,198,308,478,744,1156,1796,2792,4339,
%T A240841 6742,10477,16282,25302,39318,61100,94947,147545,229281,356295,553672,
%U A240841 860388,1337014,2077676,3228640,5017200,7796562,12115600,18827241,29256909,45464268
%N A240841 a(n) = floor(8^n/(1+2*sin(6*Pi/13)/(2*sin(Pi/13)))^n).
%C A240841 a(n) is the perimeter (rounded down) of a tridecaflake after n iterations, let a(0) = 1. The total number of sides is 13*A001018(n). The total number of holes is A091030(n), n >= 1.
%H A240841 Kival Ngaokrajang, <a href="/A240841/a240841.pdf">Illustration of tridecaflake for n = 0..3</a>
%H A240841 Wikipedia, <a href="http://en.wikipedia.org/wiki/N-flake">n-flake</a>
%p A240841 A240841:=n->floor(8^n/(1+2*sin(6*Pi/13)/(2*sin(Pi/13)))^n); seq(A240841(n), n=0..50); # _Wesley Ivan Hurt_, Apr 13 2014
%t A240841 Table[Floor[8^n/(1 + 2*Sin[6*Pi/13]/(2*Sin[Pi/13]))^n], {n, 0, 50}] (* _Wesley Ivan Hurt_, Apr 13 2014 *)
%o A240841 (PARI) {a(n)=floor(8^n/(1+2*sin(6*Pi/13)/(2*sin(Pi/13)))^n)}
%Y A240841 Cf. A001018, A091030, A240523 (pentaflake), A240671 (heptaflake), A240572 (octaflake), A240733 (nonaflake), A240734 (decaflake), A240840 (hendecaflake), A240735 (dodecaflake).
%K A240841 nonn,easy
%O A240841 0,3
%A A240841 _Kival Ngaokrajang_, Apr 13 2014