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 A380941 #9 Feb 09 2025 20:10:38 %S A380941 1,0,1,6,4,4,3,4,4,6,8,9,6,3,3,0,1,5,0,1,6,0,0,9,7,5,5,1,5,1,7,0,6,9, %T A380941 6,4,3,6,3,7,9,2,8,8,9,2,9,0,6,3,9,9,6,5,7,7,8,9,0,0,8,2,7,6,2,8,3,2, %U A380941 0,7,1,2,9,7,4,4,1,3,1,7,4,2,5,0,6,8,9,8,5,4 %N A380941 Decimal expansion of the middle vertex angle, in radians, in a disdyakis triacontahedron face. %C A380941 A disdyakis triacontahedron face is a scalene triangle with three acute angles. %H A380941 Paolo Xausa, <a href="/A380941/b380941.txt">Table of n, a(n) for n = 1..10000</a> %H A380941 Wikipedia, <a href="https://en.wikipedia.org/wiki/Disdyakis_triacontahedron">Disdyakis triacontahedron</a>. %F A380941 Equals arccos((17 - 4*A001622)/20). %F A380941 Equals Pi - A380940 - A380942. %e A380941 1.016443446896330150160097551517069643637928892906... %t A380941 First[RealDigits[ArcCos[(17 - 4*GoldenRatio)/20], 10, 100]] %Y A380941 Cf. A380940 (smallest face angle), A380942 (largest face angle). %Y A380941 Cf. A001622, A379388, A379708, A379709, A379710, A379711. %K A380941 nonn,cons,easy %O A380941 1,4 %A A380941 _Paolo Xausa_, Feb 08 2025