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A019827 Decimal expansion of sine of 18 degrees. 10
3, 0, 9, 0, 1, 6, 9, 9, 4, 3, 7, 4, 9, 4, 7, 4, 2, 4, 1, 0, 2, 2, 9, 3, 4, 1, 7, 1, 8, 2, 8, 1, 9, 0, 5, 8, 8, 6, 0, 1, 5, 4, 5, 8, 9, 9, 0, 2, 8, 8, 1, 4, 3, 1, 0, 6, 7, 7, 2, 4, 3, 1, 1, 3, 5, 2, 6, 3, 0, 2, 3, 1, 4, 0, 9, 4, 5, 1, 2, 2, 4, 8, 5, 3, 6, 0, 3, 6, 0, 2, 0, 9, 4, 6, 9, 5, 5, 6, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Decimal expansion of cosine of 72 degrees.

If the offset is changed to 1, the constant is 3.090169.. = 5/A001622 [Omar E. Pol, Nov 15 2007]

Also the imaginary part of i^(1/5). [Stanislav Sykora, Apr 25 2012]

LINKS

Zak Seidov, Table of n, a(n) for n = 0..999

Wikipedia, Exact trigonometric constants

FORMULA

Equals (sqrt(5)-1)/4.

Equals 1/(1+sqrt(5)). [Omar E. Pol, Nov 15 2007]

EXAMPLE

(sqrt(5)-1)/4=0.309016994374947424102293417182819...

CROSSREFS

Sequence in context: A068607 A167004 A239798 * A201581 A164597 A167295

Adjacent sequences:  A019824 A019825 A019826 * A019828 A019829 A019830

KEYWORD

nonn,cons,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified December 20 15:01 EST 2014. Contains 252266 sequences.