A375194 Decimal expansion of the sagitta of a regular 12-gon with unit side length.

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

Offset

-1,1

Links

Paolo Xausa, Table of n, a(n) for n = -1..10000

Eric Weisstein's World of Mathematics, Regular Polygon.

Eric Weisstein's World of Mathematics, Sagitta

Index entries for algebraic numbers, degree 4.

Formula

Equals tan(Pi/24)/2 = A343062/2.

Equals A188887 - A375193.

Example

0.0658262487936979267357632287048585517964070511116...

Mathematica

First[RealDigits[Tan[Pi/24]/2, 10, 100]]

Prog

(PARI) tan(Pi/24)/2
(PARI) polrootsreal(16*x^4+64*x^3+8*x^2-16*x+1)[3] \\ Charles R Greathouse IV, Feb 05 2025

Crossrefs

Cf. A188887 (circumradius), A375193 (apothem), A178809 (area).

Cf. sagitta of other polygons with unit side length: A020769 (triangle), A174968 (square), A375068 (pentagon), A375069 (hexagon), A374972 (heptagon), A375070 (octagon), A375153 (9-gon), A375189 (10-gon), A375192 (11-gon).

Cf. A343062.

Sequence in context: A195446 A262993 A201764 * A147313 A242759 A021607

Adjacent sequences: A375191 A375192 A375193 * A375195 A375196 A375197

Keyword

nonn,cons,easy,changed

Author

Paolo Xausa, Aug 04 2024

Status

approved