A280585 Decimal expansion of 8*sin(Pi/8).

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

Offset

1,1

Comments

Decimal expansion of the ratio of the perimeter of a regular 8-gon (octagon) to its diameter (largest diagonal).

Links

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

Formula

Equals 8*A182168.

Example

3.061467458920718173827679872243190934090756499885016331470405085020368271...

Maple

evalf(8*sin(Pi/8), 100); # Wesley Ivan Hurt, Feb 01 2017

Mathematica

RealDigits[8*Sin[Pi/8], 10, 120][[1]] (* Amiram Eldar, Jun 26 2023 *)

Prog

(PARI) 8*sin(Pi/8)

Crossrefs

Cf. For other n-gons: A010466 (n=4), 10*A019827 (n=5, 10), A280533 (n=7), A280633 (n=9), A280725 (n=11), A280819 (n=12).

Cf. A182168.

Sequence in context: A117784 A257896 A268978 * A359218 A197807 A111074

Adjacent sequences: A280582 A280583 A280584 * A280586 A280587 A280588

Keyword

nonn,cons

Author

Rick L. Shepherd, Jan 05 2017

Status

approved