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A019968
Decimal expansion of tangent of 70 degrees.
4
2, 7, 4, 7, 4, 7, 7, 4, 1, 9, 4, 5, 4, 6, 2, 2, 2, 7, 8, 7, 6, 1, 6, 6, 4, 0, 2, 6, 4, 9, 7, 6, 7, 2, 7, 1, 7, 7, 5, 1, 8, 7, 2, 5, 9, 9, 1, 7, 0, 8, 2, 5, 8, 2, 1, 5, 0, 5, 2, 7, 3, 0, 0, 2, 5, 1, 9, 8, 9, 8, 2, 5, 3, 8, 8, 1, 5, 9, 3, 1, 8, 4, 3, 4, 0, 6, 0, 4, 2, 4, 5, 9, 5, 0, 7, 0, 1, 8, 5
OFFSET
1,1
COMMENTS
Also the decimal expansion of cotangent of 20 degrees. - Ivan Panchenko, Sep 01 2014
An algebraic number of degree 6 and denominator 3. - Charles R Greathouse IV, Aug 27 2017
EXAMPLE
2.7474774194546222787616640264976727177518725991708258215...
MATHEMATICA
RealDigits[Tan[7*Pi/18], 10, 100][[1]] (* G. C. Greubel, Nov 21 2018 *)
PROG
(PARI) tan(7*Pi/18) \\ Charles R Greathouse IV, Aug 27 2017
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(7*Pi(R)/18); // G. C. Greubel, Nov 21 2018
(Sage) numerical_approx(tan(7*pi/18), digits=100) # G. C. Greubel, Nov 21 2018
CROSSREFS
Cf. A019879 (sine of 70 degrees).
Sequence in context: A175641 A286984 A021368 * A257434 A011050 A198935
KEYWORD
nonn,cons
STATUS
approved