A387444 Decimal expansion of cos(Pi/23).

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

Offset: 0

Author

R. J. Mathar, Aug 29 2025

Keywords

• nonn
• cons
• new

Examples

			0.99068594603633075234...
		

Links

• R. J. Mathar, Reduction formulas of the cosine of integer fractions of pi, (2008) vixra:2210.0026
• Index entries for algebraic numbers, degree 11

Crossrefs

Cf. A019690.

Formula

Equals sin(21*Pi/46).

Largest of the 11 real-valued roots of 2048*x^11 -1024*x^10 -5120*x^9 +2304*x^8 +4608*x^7 -1792*x^6 -1792*x^5 +560*x^4 +280*x^3 -60*x^2 -12*x +1 = 0.