A381153 Decimal expansion of the isoperimetric quotient of a regular heptagon.

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

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/(7*tan(Pi/7)) = Pi/(7*A343058).

Equals (4/49)*Pi*A178817.

Example

0.93194062349909574595222630089422754574528525154715...

Mathematica

First[RealDigits[Pi/(7*Tan[Pi/7]), 10, 100]]

Crossrefs

Cf. A178817, A343058.

Cf. isoperimetric quotient of other regular polygons: A073010 (triangle), A003881 (square), A381152 (pentagon), A093766 (hexagon), A196522 (octagon), A381154 (9-gon), A381155 (10-gon), A381156 (11-gon), A381157 (12-gon).

Sequence in context: A188887 A378102 A250091 * A199152 A306808 A086232

Adjacent sequences: A381149 A381150 A381152 * A381154 A381155 A381156

Keyword

nonn,cons,easy

Author

Paolo Xausa, Feb 15 2025

Status

approved