cp's OEIS Frontend

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.

A117605 Decimal expansion of the real solution to equation x^3 + 3*x = 2.

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%I A117605 #24 Mar 30 2025 16:34:41
%S A117605 5,9,6,0,7,1,6,3,7,9,8,3,3,2,1,5,2,3,1,1,2,8,0,5,4,1,4,3,9,9,6,8,1,8,
%T A117605 2,8,1,1,3,3,2,5,4,9,4,3,9,6,2,1,3,1,9,4,3,2,4,7,9,0,8,3,0,3,6,0,0,5,
%U A117605 1,6,2,6,8,6,2,0,8,9,1,8,5,8,7,1,6,6,0,3,3,7,5,4,2,8,4,7,5,4,7,3
%N A117605 Decimal expansion of the real solution to equation x^3 + 3*x = 2.
%C A117605 Let p(n,x) denote the n-th Maclaurin polynomial of e^x, and let p'(n,x) denote its derivative. Then p'(n+1,x) = p(n,x), so that the real zero r of p(n,x), for odd n, is also the value of x that minimizes p(n+1,x). Let y = 0.5960716... . Then for n = 3, we have r = - y - 1; see A332324 for the minimal value of p(4,x). - _Clark Kimberling_, Feb 13 2020
%F A117605 x = (1+sqrt(2))^(1/3) - 1/(1+sqrt(2))^(1/3).
%F A117605 From _Gerry Martens_, Mar 23 2025: (Start)
%F A117605 Equals (2/3)*hypergeom([1/3, 2/3], [3/2], -1).
%F A117605 Equals 2*sinh(asinh(1)/3). (End)
%e A117605 x = 0.596071637983321523112805414399681828113325...
%t A117605 RealDigits[N[Solve[3*z+z^3==2,z][[1,1,2]],100]][[1]]
%Y A117605 Cf. A014176, A332324.
%K A117605 cons,nonn
%O A117605 0,1
%A A117605 _Zak Seidov_, Apr 27 2006
%E A117605 a(99) corrected by _Sean A. Irvine_, Jul 25 2021