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A049470 Decimal expansion of cos(1). 31
5, 4, 0, 3, 0, 2, 3, 0, 5, 8, 6, 8, 1, 3, 9, 7, 1, 7, 4, 0, 0, 9, 3, 6, 6, 0, 7, 4, 4, 2, 9, 7, 6, 6, 0, 3, 7, 3, 2, 3, 1, 0, 4, 2, 0, 6, 1, 7, 9, 2, 2, 2, 2, 7, 6, 7, 0, 0, 9, 7, 2, 5, 5, 3, 8, 1, 1, 0, 0, 3, 9, 4, 7, 7, 4, 4, 7, 1, 7, 6, 4, 5, 1, 7, 9, 5, 1, 8, 5, 6, 0, 8, 7, 1, 8, 3, 0, 8, 9 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Also, decimal expansion of the real part of e^i. - Bruno Berselli, Feb 08 2013

LINKS

Table of n, a(n) for n=0..98.

Mohammad K. Azarian, Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813, College Mathematics Journal, Vol. 36, No. 5, November 2005, p. 413-414.

Mohammad K. Azarian, Solution of Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813, College Mathematics Journal, Vol. 37 , No. 5, November 2006, pp. 394-395.

Simon Plouffe, cos(1)

Eric Weisstein's World of Mathematics, Factorial Sums

FORMULA

Continued fraction representation: cos(1) = 1/(1 + 1/(1 + 2/(11 + 12/(29 + ... + (2*n - 2)*(2*n - 3)/((4*n^2 - 2*n - 1) + ... ))))). See A275651 for proof. Cf. A073743. - Peter Bala, Sep 02 2016

EXAMPLE

0.5403023058681397...

MATHEMATICA

RealDigits[Cos[1], 10, 110] [[1]]

PROG

(PARI) cos(1) \\ Charles R Greathouse IV, Jan 04 2016

CROSSREFS

Cf. A049469 (imaginary part of e^i), A211883 (real part of -(i^e)), A211884 (imaginary part of -(i^e)). - Bruno Berselli, Feb 08 2013

Cf. A073743 ( cosh(1) ), A275651.

Sequence in context: A159799 A185579 A197134 * A153106 A021189 A197012

Adjacent sequences:  A049467 A049468 A049469 * A049471 A049472 A049473

KEYWORD

cons,easy,nonn

AUTHOR

Albert du Toit (dutwa(AT)intekom.co.za), N. J. A. Sloane.

STATUS

approved

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Last modified August 22 10:37 EDT 2017. Contains 290946 sequences.