A019979 Decimal expansion of tangent of 81 degrees.

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

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• cons
• changed

Comments

Also the decimal expansion of cotangent of 9 degrees. - Ivan Panchenko, Sep 01 2014

Links

• Ivan Panchenko, Table of n, a(n) for n = 1..1000
• Wikipedia, Exact trigonometric constants
• Index entries for algebraic numbers, degree 8

Formula

Positive root of x^8-44*x^6+166*x^4-44*x^2+1=0. - R. J. Mathar, Aug 31 2025