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A121225 Decimal expansion of -log(2-2*cos(1))/2. 4
4, 2, 0, 1, 9, 5, 0, 5, 8, 2, 5, 3, 6, 8, 9, 6, 1, 7, 2, 5, 7, 9, 8, 3, 8, 4, 0, 3, 7, 9, 0, 2, 0, 3, 7, 1, 2, 4, 5, 3, 8, 9, 2, 0, 5, 5, 7, 0, 3, 4, 4, 1, 7, 6, 9, 9, 5, 6, 8, 8, 8, 9, 9, 6, 8, 5, 6, 8, 9, 8, 9, 9, 1, 5, 7, 2, 4, 7, 7, 1, 3, 4, 1, 1, 4, 6, 2, 9, 4, 7, 2, 7, 4, 6, 8, 4, 4, 6, 0, 4 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

-1,1

LINKS

Table of n, a(n) for n=-1..98.

Index entries for transcendental numbers

FORMULA

Equals Sum_{k>=1} cos(k)/k.

Equals -log(2*sin(1/2)). - Jianing Song, Nov 09 2019

Equals log(csc(1/2)/2). - Peter Luschny, Apr 04 2020

EXAMPLE

0.0420195058253689...

MATHEMATICA

RealDigits[N[ -Log[2 - 2 Cos[1]]/2, 101]]

PROG

(PARI) -log(2-2*cos(1))/2 \\ Charles R Greathouse IV, May 15 2019

CROSSREFS

Cf. A096444, A049470.

Sequence in context: A093556 A021242 A088393 * A216715 A049430 A055356

Adjacent sequences:  A121222 A121223 A121224 * A121226 A121227 A121228

KEYWORD

cons,nonn

AUTHOR

Fredrik Johansson, Aug 20 2006

STATUS

approved

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Last modified September 27 03:21 EDT 2020. Contains 337380 sequences. (Running on oeis4.)