A387450 Decimal expansion of cos(Pi/33).

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

Offset: 0

Author

R. J. Mathar, Aug 29 2025

Keywords

• nonn
• cons
• new

Examples

			0.99547192257308460473...
		

Links

• R. J. Mathar, Reduction formulas of the cosine of integer fractions of pi, (2008) vixra:2210.0026
• Index entries for algebraic numbers, degree 10

Formula

Equals sin(31*Pi/66) = 2F1(-1/22,1/22;1/2;3/4).

Largest of the 10 real-valued roots of 1024*x^10 +512*x^9 -2560*x^8 -1280*x^7 +2176*x^6 +1088*x^5 -688*x^4 -344*x^3 +48*x^2 +24*x +1 =0.

4*this^3 -3*this = A387440.