A157697 - OEIS

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A157697

Decimal expansion of sqrt(2/3).

8, 1, 6, 4, 9, 6, 5, 8, 0, 9, 2, 7, 7, 2, 6, 0, 3, 2, 7, 3, 2, 4, 2, 8, 0, 2, 4, 9, 0, 1, 9, 6, 3, 7, 9, 7, 3, 2, 1, 9, 8, 2, 4, 9, 3, 5, 5, 2, 2, 2, 3, 3, 7, 6, 1, 4, 4, 2, 3, 0, 8, 5, 5, 7, 5, 0, 3, 2, 0, 1, 2, 5, 8, 1, 9, 1, 0, 5, 0, 0, 8, 8, 4, 6, 6, 1, 9, 8, 1, 1, 0, 3, 4, 8, 8, 0, 0, 7, 8, 2, 7, 2, 8, 6, 4 (list; constant; graph; refs; listen; history; text; internal format)

	OFFSET	`0,1`
	COMMENTS	`Equals sum_{n=0..infinity} (-1)^n*binomial(2n,n)/8^n = 1/A115754 . Averaging this constant with sqrt(2) = A002193 = sum_{n=0..inf} binomial(2n,n)/8^n yields A145439.` `Height (from a vertex to the opposite face) of regular tetrahedron with unit edge. - Stanislav Sykora, May 31 2012`
	REFERENCES	`Jolley, Summation of Series, Dover (1961) eq. (168) on page 32.`
	LINKS	`Table of n, a(n) for n=0..104.` `D. H. Lehmer, Interesting series involving the Central Binomial Coefficient, Am. Math. Monthly 92, no 7 (1985) 449-457.`
	FORMULA	`= 1-(1/2)/2 +(13)/(24)/2^2 - (135)/(246)/2^3+... [Jolley]`
	EXAMPLE	`0.816496580927726056140063577...`
	MAPLE	`evalf(sqrt(2/3)) ;`
	MATHEMATICA	`RealDigits[N[Sqrt[2/3], 200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Mar 04 2011*)`
	CROSSREFS	`Sequence in context: A033812 A019717 A007404 * A281785 A240982 A258146` `Adjacent sequences: A157694 A157695 A157696 * A157698 A157699 A157700`
	KEYWORD	`cons,easy,nonn`
	AUTHOR	`R. J. Mathar, Mar 04 2009`
	STATUS	`approved`

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Last modified July 24 21:38 EDT 2017. Contains 289777 sequences.