A381156 Decimal expansion of the isoperimetric quotient of a regular 11-gon.

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

Offset: 0

Author

Paolo Xausa, Feb 15 2025

Keywords

• nonn
• cons
• easy

Comments

For the definition of isoperimetric quotient, see A381152.

Examples

			0.97266200091990681953828897938526763171296541114234...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 0..10000
• Eric Weisstein's World of Mathematics, Isoperimetric Quotient.
• Wikipedia, Isoperimetric inequality.

Crossrefs

Cf. A256854.

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), A381157 (12-gon).

Programs

Mathematica

First[RealDigits[Pi/(11*Tan[Pi/11]), 10, 100]]

Formula

Equals Pi/(11*tan(Pi/11)).

Equals (4/121)*Pi*A256854.