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A090388 Decimal expansion of 1 + sqrt(3). 22

%I #57 Aug 17 2023 16:53:45

%S 2,7,3,2,0,5,0,8,0,7,5,6,8,8,7,7,2,9,3,5,2,7,4,4,6,3,4,1,5,0,5,8,7,2,

%T 3,6,6,9,4,2,8,0,5,2,5,3,8,1,0,3,8,0,6,2,8,0,5,5,8,0,6,9,7,9,4,5,1,9,

%U 3,3,0,1,6,9,0,8,8,0,0,0,3,7,0,8,1,1,4,6,1,8,6,7,5,7,2,4,8,5,7,5,6

%N Decimal expansion of 1 + sqrt(3).

%C 1 + sqrt(3) is the length of the minimal Steiner network that connects the four vertices of a unit square. - _Lekraj Beedassy_, May 02 2008

%C This is the case n = 12 in the identity (Gamma(1/n)/Gamma(3/n))*(Gamma((n-1)/n)/Gamma((n-3)/n)) = 1 + 2*cos(2*Pi/n). - _Bruno Berselli_, Dec 14 2012

%C Equals n + n/(n + n/(n + n/(n + ...))) for n = 2. - _Stanislav Sykora_, Jan 23 2014

%C A non-optimal solution to the problem of finding the length of shortest fence that protects privacy of a square garden [Kawohl]. Cf. A256965. - _N. J. A. Sloane_, Apr 14 2015

%C Perimeter of a 30-60-90 triangle with longest leg equal to 1. - _Wesley Ivan Hurt_, Apr 09 2016

%C Length of the second shortest diagonal in a regular 12-gon with unit side. - _Mohammed Yaseen_, Dec 13 2020

%H G. C. Greubel, <a href="/A090388/b090388.txt">Table of n, a(n) for n = 1..10000</a>

%H Bernd Kawohl, <a href="http://www.mi.uni-koeln.de/mi/Forschung/Kawohl/kawohl/springercime.ps">Some nonconvex shape optimization problems, in: Optimal Shape Design</a>, Eds. A.Cellina u. A. Ornelas, Springer Lecture Notes in Math.1740 (2000), p. 7-46.

%H Ian Stewart, <a href="http://www.mi.uni-koeln.de/mi/Forschung/Kawohl/various/Bilder/PolygonalPrivacy.pdf">Pursuing Polygonal Privacy</a>, Mathematical Recreations Column, Scientific American, 284 (No. 2, 2001), 88-89.

%H <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>

%F Equals 1 + A002194. - _R. J. Mathar_, Oct 16 2015

%F Equals A019973 -1 . - _R. J. Mathar_, May 25 2023

%e 2.7320508075688772...

%p Digits:=100: evalf((1+sqrt(3))); # _Wesley Ivan Hurt_, Apr 09 2016

%t RealDigits[1 + Sqrt[3], 10, 100][[1]] (* _Alonso del Arte_, Feb 23 2014 *)

%o (PARI) 1 + sqrt(3) \\ _Michel Marcus_, Apr 10 2016

%Y Cf. n + n/(n + n/(n + ...)): A090458 (n = 3), A090488 (n = 4), A090550 (n = 5), A092294 (n = 6), A092290 (n = 7), A090654 (n = 8), A090655 (n = 9), A090656 (n = 10). - _Stanislav Sykora_, Jan 23 2014

%Y Cf., also A256965.

%K easy,nonn,cons

%O 1,1

%A _Felix Tubiana_, Feb 05 2004

%E Better definition from _Rick L. Shepherd_, Jul 02 2004

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Last modified April 25 07:41 EDT 2024. Contains 371964 sequences. (Running on oeis4.)