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1,1
Also, 2 + sqrt(3) = cotangent of 15 degrees. - Rick L. Shepherd, Jul 04 2004
An equivalent definition of this sequence: decimal expansion of x > 1 satisfying x^2 - 4*x + 1 = 0. - Arkadiusz Wesolowski, Nov 28 2011
Ivan Panchenko, Table of n, a(n) for n = 1..1000
Wikipedia, Exact trigonometric constants
RealDigits[Tan[75 Degree], 10, 120][[1]] (* Harvey P. Dale, Nov 08 2011 *)
Cf. A002194 (sqrt(3)).
Sequence in context: A256978 A021272 A135613 * A010623 A066065 A145511
Adjacent sequences: A019970 A019971 A019972 * A019974 A019975 A019976
nonn,cons
N. J. A. Sloane.
Checked by Neven Juric (neven.juric(AT)apis-it.hr), Feb 04 2008
approved