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 A338004 #13 Feb 05 2025 00:19:19 %S A338004 6,6,3,4,8,2,9,7,0,5,1,1,4,3,4,8,0,8,0,5,7,5,6,8,8,4,7,4,3,7,2,3,9,9, %T A338004 5,0,0,0,5,0,4,2,8,9,8,5,1,5,6,9,6,2,5,5,4,5,7,1,8,2,4,4,9,9,5,0,5,9, %U A338004 3,3,1,5,0,9,3,7,7,6,8,3,8,5,0,6,8,1,0,9,7,9,1,5,6,8,7,8,5,8,9,8,7,3,3,3,0,1,0,9,0,8,3,3,8,9,1,3,9,4,5,4 %N A338004 Decimal expansion of the angle of association yielding the gyroid relative to Schwarz's D surface. %C A338004 For every minimal surface, an associate family of minimal surfaces can be defined by adding an angle of association to the base surface's Weierstrass-Enneper parametrization. %C A338004 If the base is Schwarz's D surface, an angle of association of Pi/2 yields Schwarz's P surface; this entry is the only other angle for which the resulting associate surface - the gyroid - is embedded. %H A338004 A. Schoen, <a href="https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700020472.pdf">Infinite Periodic Minimal Surfaces Without Self-Intersections</a>, NASA Technical Note D-5541, 1970. %H A338004 A. Schoen, <a href="https://schoengeometry.com/e-tpms.html">Triply-periodic minimal surfaces</a> %H A338004 Wikipedia, <a href="https://en.wikipedia.org/wiki/Associate_family">Associate family</a> %F A338004 Equals arctan(K(1/4) / K(3/4)), where K is the complete elliptic integral of the first kind. %e A338004 0.66348297051143480805756884743723... %e A338004 In degrees: 38.0147739891080681076130861019883... %t A338004 First@ RealDigits@ N[ArcTan[EllipticK[1/4] / EllipticK[3/4]], 120] %o A338004 (PARI) atan(ellK(1/2)/ellK(sqrt(3/4))) \\ _Charles R Greathouse IV_, Feb 05 2025 %Y A338004 Cf. A249282 (K(1/4)), A249283 (K(3/4)). %K A338004 nonn,cons %O A338004 0,1 %A A338004 _Jeremy Tan_, Oct 06 2020