A115754 Decimal expansion of sqrt(3/2).

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

Offset

1,2

Comments

Coordinate of a control point for a degree-5 integration formula for 7 points over the unit circle. [Stroud & Secrest]

Also real and imaginary part of sqrt(-3i). - Alonso del Arte, Dec 11 2012

Area of the quadrilateral obtained when slicing a unit cube with a plane passing through opposite vertices and the middle of opposite edges. See CNRS link. - Michel Marcus, Mar 26 2016

Links

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Ana Rechtman, Mars 2016, 3e défi, Images des Mathématiques, CNRS, 2016.

A. H. Stroud, D. Secrest, Approximate integration formulas for certain spherically symmetric regions, Math. Comp. 17 (82) (1963) 105.

Index entries for algebraic numbers, degree 2

Formula

Equals 2*A187110.

Equals Sum_{k>=0} binomial(1/2, k)/2^k. - Bruno Berselli, Sep 11 2015

From Amiram Eldar, Aug 02 2020: (Start)

Equals Product_{k>=0} (1 + (-1)^k/(6*k + 3)).

Equals Sum_{k>=0} binomial(2*k,k)/12^k.

Equals 1 + Sum_{k>=1} (2*k - 1)!!/((2*k)!! * 3^k). (End)

Equals A010464/2. - R. J. Mathar, Feb 23 2021

Example

1.2247448713915890490986420373529456959829737403283350642163...

Mathematica

RealDigits[Sqrt[3/2], 10, 105][[1]] (* Alonso del Arte, Dec 11 2012 *)

Crossrefs

Cf. A010464 (double), A187110 (half), A157697 (reciprocal).

Sequence in context: A212362 A209142 A368518 * A210600 A220308 A203975

Adjacent sequences: A115751 A115752 A115753 * A115755 A115756 A115757

Keyword

nonn,easy,cons

Author

Eric Desbiaux, Jul 30 2008

Status

approved