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A118292 Decimal expansion of (Gamma[1/6]*Gamma[1/3])/(3*Sqrt[Pi]). 5
2, 8, 0, 4, 3, 6, 4, 2, 1, 0, 6, 5, 0, 9, 0, 8, 5, 2, 2, 3, 5, 0, 0, 3, 8, 1, 5, 8, 1, 0, 0, 5, 8, 8, 2, 7, 0, 9, 2, 6, 0, 4, 4, 4, 1, 0, 8, 4, 7, 9, 7, 2, 1, 9, 2, 3, 6, 3, 9, 8, 7, 9, 7, 4, 1, 5, 2, 5, 6, 9, 5, 3, 1, 9, 6, 3, 6, 0, 6, 5, 9, 2, 1, 4, 1, 7, 0, 4, 5, 3, 2, 9, 7, 0, 0, 4, 9, 5, 6, 9, 4, 1, 1, 0, 3 (list; constant; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

General formula (*Artur Jasinski*): Integrate[(1+x^(3n))/Sqrt[1-x^3],{x,0,1}] = G_3 * k_n = G_3*A146751(n)/A146752(n) = A118292*A146751(n)/A146752(n) where G_3 = (Gamma[1/3]^3)/(2^(1/3)Sqrt[3]Pi) is the number in the present entry. For numerators of k_n see A146752, for denominators of k_n see A146753.

gamma(1/6)*gamma(1/3)/(3*sqrt(Pi)) = gamma(1/3)^3/(2^(1/3)*sqrt(3)*Pi) [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009]

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,4000

Eric Weisstein's World of Mathematics, Butterfly Curve

FORMULA

Equals A073005^3 / (A002194*A002580*A000796) [see Vidunas, arXiv:math.CA/0403510] [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 30 2008]

EXAMPLE

2.8043642106509085223...

2.8043642106509085223500381581005882709260444108479721923639879741525695... [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009]

MATHEMATICA

RealDigits[(Gamma[1/3]^3)/(2^(1/3) Sqrt[3] Pi), 10, 200] (*Artur Jasinski*)

PROG

(PARI) { allocatemem(932245000); default(realprecision, 4080); x=gamma(1/3)^3/(2^(1/3)*sqrt(3)*Pi); for (n=1, 4000, d=floor(x); x=(x-d)*10; write("b118292.txt", n, " ", d)); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jun 20 2009]

CROSSREFS

Cf. A146752, A146753

Cf. A160323 = Continued fraction. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009]

Sequence in context: A021785 A136664 A086728 * A160584 A191334 A188924

Adjacent sequences:  A118289 A118290 A118291 * A118293 A118294 A118295

KEYWORD

nonn,cons

AUTHOR

Eric Weisstein (eric(AT)weisstein.com), Apr 22, 2006

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Nov 16 2008 at the suggestion of R. J. Mathar

Fixed my PARI program, had -n Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 19 2009

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Last modified February 16 04:47 EST 2012. Contains 205860 sequences.