OFFSET
0,1
COMMENTS
Pólya (1921) proved that this constant is < 1. McCrea and Whipple (1940) evaluated it by 0.34. - Amiram Eldar, Aug 28 2020
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, p. 322-331.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..10000
W. H. McCrea and F. J. W. Whipple, Random Paths in Two and Three Dimensions, Proceedings of the Royal Society of Edinburgh, Vol. 60, No. 3 (1940), pp. 281-298. See p. 297.
Georg Pólya, Über eine Aufgabe der Wahrscheinlichkeitsrechnung betreffend die Irrfahrt im Straßennetz, Mathematische Annalen, Vol. 84, No. 1-2 (1921), pp. 149-160.
Eric Weisstein's World of Mathematics, Pólya's Random Walk Constants.
FORMULA
Equals 1 - (16*Sqrt(2/3)*Pi^3)/(Gamma(1/24)* Gamma(5/24)*Gamma(7/24)* Gamma(11/24)). - G. C. Greubel, Jan 25 2018
Equals 1 - 1/A086231. - Amiram Eldar, Aug 28 2020
EXAMPLE
0.340537329550999142826273184432902896710608217124302097763236105377791969...
MATHEMATICA
RealDigits[1 - (16*Sqrt[2/3]*Pi^3) / (Gamma[1/24]*Gamma[5/24]*Gamma[7/24]*Gamma[11/24]), 10, 102] // First (* Jean-François Alcover, Feb 08 2013, after Eric W. Weisstein *)
PROG
(PARI) 1-32*Pi^3/sqrt(6)/gamma(1/24)/gamma(5/24)/gamma(7/24)/gamma(11/24) \\ Charles R Greathouse IV, Jul 22 2013
(Magma) C<i> := ComplexField(); 1 - (16*Sqrt(2/3)*Pi(C)^3)/(Gamma(1/24)* Gamma(5/24)*Gamma(7/24)*Gamma(11/24)); // G. C. Greubel, Jan 25 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Jul 12 2003
STATUS
approved