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A019827 Decimal expansion of sine of 18 degrees. 8
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 September 18 03:41 EDT 2014. Contains 246887 sequences.