A280725 Decimal expansion of 22*sin(Pi/22).

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

Offset

1,1

Comments

The ratio of the perimeter of a regular 11-gon (hendecagon) to its diameter (largest diagonal).

Also least positive root of x^5 - 11x^4 - 484x^3 + 3993x^2 + 43923x - 161051.

Links

Table of n, a(n) for n=1..105.

Example

3.130926442012273089763438709560132713403129944771655225197821304298120771...

Maple

evalf(22*sin(Pi/22), 100); # Wesley Ivan Hurt, Feb 01 2017

Mathematica

RealDigits[22*Sin[Pi/22], 10, 120][[1]] (* Amiram Eldar, Jun 26 2023 *)

Prog

(PARI) 22*sin(Pi/22)

Crossrefs

Cf. For other n-gons: A010466 (n=4), 10*A019827 (n=5, 10), A280533 (n=7), A280585 (n=8), A280633 (n=9), A280819 (n=12).

Sequence in context: A079530 A020815 A233931 * A243328 A243332 A156872

Adjacent sequences: A280722 A280723 A280724 * A280726 A280727 A280728

Keyword

nonn,cons

Author

Rick L. Shepherd, Jan 07 2017

Status

approved