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0,1
This sequence is also decimal expansion of cosine of 48 degrees. - Mohammad K. Azarian, Jun 29 2013
Ivan Panchenko, Table of n, a(n) for n = 0..1000
Wikipedia, Exact trigonometric constants
Equals cos (4*Pi/15) = [sqrt(5)-1]*[sqrt(3)*sqrt{5+2*sqrt(5)}-1]/8 = 8*A019887^4 -8*A019887^2+1 = sqrt(1-A019857^2) - R. J. Mathar, Jun 18 2006
Sequence in context: A083507 A157320 A200616 * A155880 A217852 A021603
Adjacent sequences: A019848 A019849 A019850 * A019852 A019853 A019854
nonn,cons
N. J. A. Sloane.
approved