The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com
0,1
This sequence is also decimal expansion of cosine of 54 degrees. - Mohammad K. Azarian, Jun 29 2013
The ratio side/(longer diagonal) for any golden rhombus (see A019881). - Rick L. Shepherd, Apr 10 2017
Zak Seidov, Table of n, a(n) for n = 0..999
Wikipedia, Exact trigonometric constants
Equals A019881/A001622. - Rick L. Shepherd, Apr 10 2017
sqrt((1/8)*(5 - sqrt(5))) = 0.5877852522924731291687059546390...
(PARI) sin(Pi/5) \\ Michel Marcus, Apr 25 2015
(PARI) cos(3*Pi/10) \\ Rick L. Shepherd, Apr 10 2017
(PARI) real(I^(3/5)) \\ Rick L. Shepherd, Apr 10 2017
Cf. A019827 (sine of 18 degrees), A019881 (sine of 72 degrees), A001622 (golden ratio phi).
Sequence in context: A243598 A230366 A197415 * A143618 A177056 A053787
Adjacent sequences: A019842 A019843 A019844 * A019846 A019847 A019848
nonn,cons
N. J. A. Sloane.
approved