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A094641 Continued fraction for the "alternating Euler constant" log(4/Pi). 3
0, 4, 7, 6, 3, 1, 1, 9, 1, 1, 4, 26, 1, 2, 4, 1, 9, 1, 20, 3, 1, 12, 1, 2, 7, 1, 5, 2, 1, 5, 3, 1, 1, 1, 4, 1, 1, 57, 1, 2, 1, 8, 8, 1, 1, 1, 1, 1, 22, 1, 1, 6, 1, 6, 6, 1, 3, 1, 4, 2, 2, 2, 4, 1, 1, 2, 1, 19, 17, 348, 1, 1, 5, 16, 2, 2, 5, 1, 5, 2, 4, 2, 5, 1, 11, 1, 1, 11, 13, 2, 1, 1, 5, 2, 1, 2, 10, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See the Comments in A094640 for why log(4/Pi) is an "alternating Euler constant."

REFERENCES

G. Boros and V. Moll, Irresistible Integrals: Symbolics, Analysis and Experiments in the Evaluation of Integrals, Cambridge University Press, Cambridge, 2004, Chap. 7.

J. Borwein and P. Borwein, Pi and the AGM, John Wiley & Sons, New York, 1987, Chap. 11.

LINKS

Table of n, a(n) for n=1..99.

D. Huylebrouck, Similarities in irrationality proofs for Pi, ln2, zeta(2) and zeta(3), Amer. Math. Monthly 108 (2001) 222-231.

J. Sondow, Double Integrals for Euler's Constant and ln(4/Pi) and an Analog of Hadjicostas's Formula, Amer. Math. Monthly 112 (2005) 61-65.

J. Sondow, New Vacca-Type Rational Series for Euler's Constant and Its "Alternating" Analog ln(4/Pi), Additive Number Theory, Festschrift In Honor of the Sixtieth Birthday of Melvyn B. Nathanson (D. Chudnovsky and G. Chudnovsky, eds.), Springer, 2010, pp. 331-340.

J. Sondow and P. Hadjicostas, The generalized-Euler-constant function gamma(z) and a generalization of Somos's quadratic recurrence constant, J. Math. Anal. Appl. 332 (1) (2007), 292-314.

EXAMPLE

log(4/Pi) = 0 + 1/(4 + 1/(7 + 1/(6 + 1/(3 + 1/(1 + ...)))))

MATHEMATICA

ContinuedFraction[ Log[4/Pi], 100]

CROSSREFS

Cf. A094640 (decimal expansion of log(4/Pi)).

Sequence in context: A200386 A021025 A078974 * A200021 A112518 A228715

Adjacent sequences:  A094638 A094639 A094640 * A094642 A094643 A094644

KEYWORD

cofr,easy,nonn

AUTHOR

Jonathan Sondow and Robert G. Wilson v, May 18 2004

STATUS

approved

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Last modified February 17 16:26 EST 2018. Contains 299296 sequences. (Running on oeis4.)