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 A365164 #9 Aug 24 2023 07:07:15 %S A365164 6,1,2,2,9,3,4,9,1,7,8,4,1,4,3,6,3,4,7,6,5,5,3,5,9,7,4,4,4,8,6,3,8,1, %T A365164 8,6,8,1,8,1,5,1,2,9,9,9,7,7,0,0,3,2,6,6,2,9,4,0,8,1,0,1,7,0,0,4,0,7, %U A365164 3,6,5,4,3,3,6,1,4,3,5,0,7,5,7,9,2,2,2,0,5,6,5,4,7,6,5,3,6,7,5,4,3,7,4,7,8,8,6,1,8 %N A365164 Length of the perimeter of the regular octagon with unit circumradius. %F A365164 Equals 8*A101464. %e A365164 6.122934917841436347655359744486... %t A365164 f[R_, s_] := 2*R*s*Sin[Pi/s]; a[n_] := RealDigits[f[1, 8], 10, n][[1]]; a[109] (* _Robert P. P. McKone_, Aug 24 2023 *) %Y A365164 Cf. A019845 (5-gon), A010487 (4-gon), A365163 (7-gon), A365165 (9-gon), A101464 (edge length), A010466 (area). %K A365164 cons,nonn %O A365164 1,1 %A A365164 _R. J. Mathar_, Aug 24 2023