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 A381156 #7 Feb 15 2025 16:49:48 %S A381156 9,7,2,6,6,2,0,0,0,9,1,9,9,0,6,8,1,9,5,3,8,2,8,8,9,7,9,3,8,5,2,6,7,6, %T A381156 3,1,7,1,2,9,6,5,4,1,1,1,4,2,3,4,2,8,8,2,7,3,7,9,8,9,0,4,7,0,0,5,8,7, %U A381156 1,2,6,7,8,3,2,5,6,9,3,0,8,0,2,3,1,7,8,7,5,0 %N A381156 Decimal expansion of the isoperimetric quotient of a regular 11-gon. %C A381156 For the definition of isoperimetric quotient, see A381152. %H A381156 Paolo Xausa, <a href="/A381156/b381156.txt">Table of n, a(n) for n = 0..10000</a> %H A381156 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IsoperimetricQuotient.html">Isoperimetric Quotient</a>. %H A381156 Wikipedia, <a href="https://en.wikipedia.org/wiki/Isoperimetric_inequality">Isoperimetric inequality</a>. %F A381156 Equals Pi/(11*tan(Pi/11)). %F A381156 Equals (4/121)*Pi*A256854. %e A381156 0.97266200091990681953828897938526763171296541114234... %t A381156 First[RealDigits[Pi/(11*Tan[Pi/11]), 10, 100]] %Y A381156 Cf. A256854. %Y A381156 Cf. isoperimetric quotient of other regular polygons: A073010 (triangle), A003881 (square), A381152 (pentagon), A093766 (hexagon), A381153 (heptagon), A196522 (octagon), A381154 (9-gon), A381155 (10-gon), A381157 (12-gon). %K A381156 nonn,cons,easy %O A381156 0,1 %A A381156 _Paolo Xausa_, Feb 15 2025