A019908 Decimal expansion of tangent of 10 degrees.

1, 7, 6, 3, 2, 6, 9, 8, 0, 7, 0, 8, 4, 6, 4, 9, 7, 3, 4, 7, 1, 0, 9, 0, 3, 8, 6, 8, 6, 8, 6, 1, 8, 9, 8, 6, 1, 2, 1, 6, 3, 3, 0, 6, 2, 3, 4, 8, 0, 9, 8, 6, 6, 0, 2, 0, 5, 3, 6, 3, 9, 8, 3, 8, 3, 5, 4, 4, 6, 9, 0, 8, 9, 1, 7, 7, 5, 8, 6, 2, 5, 4, 9, 8, 6, 5, 1, 3, 3, 5, 0, 8, 0, 3, 2, 4, 4, 5, 3

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• cons
• changed

Comments

Also the decimal expansion of cotangent of 80 degrees. - Mohammad K. Azarian, Jun 30 2013

Examples

			0.176326980708464973471090386868618986121633...
		

Links

• Ivan Panchenko, Table of n, a(n) for n = 0..1000
• Index entries for algebraic numbers, degree 6.

Crossrefs

Cf. A019918.

Programs

Mathematica

RealDigits[Tan[10 Degree],10,120][[1]] (* Harvey P. Dale, Oct 14 2012 *)

PARI

tan(Pi/18) \\ Hugo Pfoertner, Aug 04 2024

Formula

A root of 3*x^6 -27*x^4 +33*x^2 -1 =0 (others A019968, A019948). - R. J. Mathar, Aug 29 2025