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Decimal expansion of 1 - 1/sqrt(5).
1

%I #17 Dec 09 2018 07:56:47

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

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

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

%N Decimal expansion of 1 - 1/sqrt(5).

%C Continued fraction: [0;1,1,4,4,4...].

%C Least root of the polynomial: 5x^2 - 10x + 4.

%F Equals 1 - 1/A002163.

%F Equals 1/(1 - cos(4*Pi/5)) = (1/2)*csc(2*Pi/5)^2.

%F Also equal to 2/(phi*sqrt(5)) = 2/(A001622*A002163).

%F Equals 1 - A020762. - _Andrew Howroyd_, Nov 30 2018

%e 0.552786404500042060718165266253744752911876328077...

%p evalf[110](1-1/sqrt(5)); # _Muniru A Asiru_, Dec 01 2018

%t RealDigits[1-1/Sqrt[5], 10, 100][[1]] (* _Amiram Eldar_, Nov 29 2018 *)

%Y Cf. A002163, A001622, A020762.

%K cons,easy,nonn

%O 0,1

%A _Tristan Cam_, Nov 29 2018