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 A342571 Decimal expansion of the surface area of a golden ellipsoid with semi-axes lengths 1, 1 and phi (A001622). 0
 1, 7, 9, 8, 0, 7, 9, 7, 4, 3, 4, 1, 0, 4, 7, 7, 3, 4, 2, 1, 5, 2, 4, 5, 4, 9, 5, 9, 0, 4, 3, 9, 6, 3, 8, 8, 2, 0, 4, 2, 6, 5, 9, 3, 5, 0, 6, 0, 0, 7, 3, 9, 8, 3, 9, 3, 1, 0, 3, 2, 3, 4, 8, 7, 8, 1, 2, 8, 3, 0, 6, 7, 3, 4, 6, 6, 7, 3, 3, 5, 5, 7, 3, 3, 3, 9, 2 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 LINKS Table of n, a(n) for n=2..88. Kenneth Brecher, The "PhiTOP": A Golden Ellipsoid, Proceedings of Bridges 2015: Mathematics, Music, Art, Architecture, Culture, 2015, pp. 371-374. Kenneth Brecher and Rod Cross, Physics of the PhiTOP, The Physics Teacher, Vol. 57, No. 2 (2019), pp. 74-75. Eric Weisstein's World of Mathematics, Ellipsoid. Wikipedia, Ellipsoid. FORMULA Equals 2*Pi*(1 + phi*c/sin(c)), where c = arccos(1/phi) (A195692). Equals 2*Pi*(1 + sqrt(2+sqrt(5))*arcsec(phi)). EXAMPLE 17.9807974341047734215245495904396388204265935060073... MATHEMATICA RealDigits[SurfaceArea[Ellipsoid[{0, 0, 0}, {1, 1, GoldenRatio}]], 10, 100][[1]] (* requires Mathematica 12+, or *) RealDigits[2*Pi*(1 + GoldenRatio/Sinc[ArcCos[1/GoldenRatio]]), 10, 100][[1]] CROSSREFS Cf. A001622, A195692, A309282. Sequence in context: A010729 A340220 A182688 * A372253 A256924 A348668 Adjacent sequences: A342568 A342569 A342570 * A342572 A342573 A342574 KEYWORD nonn,cons AUTHOR Amiram Eldar, Mar 27 2021 STATUS approved

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Last modified June 17 05:47 EDT 2024. Contains 373432 sequences. (Running on oeis4.)