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A185280 Decimal expansion of a constant appearing in the solution of Polya's 2D drunkard problem. 2
8, 8, 2, 5, 4, 2, 4, 0, 0, 6, 1, 0, 6, 0, 6, 3, 7, 3, 5, 8, 5, 8, 2, 5, 7, 2, 8, 4, 7, 1, 9, 9, 0, 7, 6, 3, 9, 3, 0, 7, 5, 8, 9, 9, 4, 9, 1, 8, 6, 2, 1, 8, 8, 1, 9, 5, 7, 0, 5, 2, 9, 3, 4, 8, 2, 8, 4, 8, 7, 0, 6, 8, 1, 8, 6, 7, 4, 6, 7, 2, 9, 9, 9, 1, 9, 7, 2, 4, 4, 7, 4, 1, 5, 8, 7, 0, 2, 2, 3, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..99.

P. Flajolet and R. Sedgewick, Analytic Combinatorics, 2009; p. 425-426.

FORMULA

1 + Sum_{n>=1} binomial(2*n, n)^2/16^n - 1/(Pi*n).

Equals 1 + (4*log(2) - Pi)/Pi.

Equals 4*log(2)/Pi. - Michel Marcus, Jul 28 2016

EXAMPLE

0.882542400610606373585825728471990763930758994918621881957052934828487068186...

MATHEMATICA

1+(4*Log[2]-Pi)/Pi // N[#, 100]& // RealDigits // First

PROG

(PARI) 4*log(2)/Pi \\ Michel Marcus, Jul 28 2016

CROSSREFS

Cf. A016639.

Sequence in context: A105193 A178678 A217459 * A344074 A011464 A019871

Adjacent sequences:  A185277 A185278 A185279 * A185281 A185282 A185283

KEYWORD

nonn,cons,easy

AUTHOR

Jean-Fran├žois Alcover, Apr 23 2013

STATUS

approved

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Last modified June 22 15:24 EDT 2021. Contains 345386 sequences. (Running on oeis4.)