A235916 Decimal expansion of 3/sqrt(2*Pi).

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

Offset: 1

Author

Rick L. Shepherd, Jan 16 2014

Keywords

• nonn
• cons

Comments

The radius of the large circle, the a-value in the MathWorld link, of a deltoid (3-cusped hypocycloid) with area 1. Thus, for any r > 0, this particular a*sqrt(r) is the radius of the large circle of a deltoid with area r. The radius of the small circle is a*sqrt(r)/3 = A231863*sqrt(r), because A231863 is the radius of the small circle, the b-value in the MathWorld link, of a deltoid with area 1.

Examples

			1.1968268412042980338198381798031456054275758934948039729977774890119737...
		

Links

• Rick L. Shepherd, Table of n, a(n) for n = 1..20000
• MathWorld, Deltoid
• Index entries for transcendental numbers

Crossrefs

Cf. A019727, A019728, A231863 (corresponding small circle radius).

Programs

Magma

SetDefaultRealField(RealField(100)); R:= RealField(); 3/Sqrt(2*Pi(R)); // G. C. Greubel, Sep 30 2018

Mathematica

RealDigits[N[3/Sqrt[2Pi],105]] [[1]]

PARI

default(realprecision, 120); 3/sqrt(2*Pi)

Formula

3/sqrt(2*Pi) = 3/A019727 = 3*A231863 = 1/A019728.