A381157 Decimal expansion of the isoperimetric quotient of a regular 12-gon.

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

Offset

0,1

Comments

For the definition of isoperimetric quotient, see A381152.

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

Eric Weisstein's World of Mathematics, Isoperimetric Quotient.

Wikipedia, Isoperimetric inequality.

Formula

Equals Pi/(12*tan(Pi/12)) = Pi/(12*A019913).

Equals (1/36)*Pi*A178809.

Example

0.97704861665685333572562679495712274710387812858570...

Mathematica

First[RealDigits[Pi/(12*Tan[Pi/12]), 10, 100]]

Crossrefs

Cf. A019913, A178809.

Cf. isoperimetric quotient of other regular polygons: A073010 (triangle), A003881 (square), A381152 (pentagon), A093766 (hexagon), A381153 (heptagon), A196522 (octagon), A381154 (9-gon), A381155 (10-gon), A381156 (11-gon).

Sequence in context: A247600 A281197 A373507 * A199503 A242714 A307715

Adjacent sequences: A381154 A381155 A381156 * A381159 A381160 A381161

Keyword

nonn,cons,easy

Author

Paolo Xausa, Feb 15 2025

Status

approved