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 A380704 #6 Jan 31 2025 04:20:55 %S A380704 1,4,2,3,8,2,1,1,3,6,1,3,1,3,9,1,5,4,9,4,4,5,5,5,7,3,5,6,6,6,6,9,0,4, %T A380704 6,8,4,8,8,5,7,9,7,9,9,0,2,9,5,1,0,1,3,5,9,0,4,7,9,1,8,9,5,6,3,9,5,0, %U A380704 2,3,1,3,5,2,9,6,2,1,8,6,1,2,5,7,8,9,9,9,6,0 %N A380704 Decimal expansion of the acute vertex angles, in radians, in a deltoidal icositetrahedron face. %H A380704 Paolo Xausa, <a href="/A380704/b380704.txt">Table of n, a(n) for n = 1..10000</a> %H A380704 Wikipedia, <a href="https://en.wikipedia.org/wiki/Deltoidal_icositetrahedron">Deltoidal icositetrahedron</a>. %F A380704 Equals arccos(1/2 - sqrt(2)/4) = arccos(1/2 - A020765). %F A380704 Equals (2*Pi - A380705)/3. %e A380704 1.4238211361313915494455573566669046848857979902951... %t A380704 First[RealDigits[ArcCos[1/2 - Sqrt[2]/4], 10, 100]] %Y A380704 Cf. A380705 (obtuse face angle). %Y A380704 Cf. A020765, A378390, A378391, A378392, A378393, A378394. %K A380704 nonn,cons,easy %O A380704 1,2 %A A380704 _Paolo Xausa_, Jan 31 2025