OFFSET
0,1
LINKS
Jonathan M. Borwein, Armin Straub, James Wan, and Wadim Zudilin, Densities of Short Uniform Random Walks p. 974, Canad. J. Math. 64(2012), 961-990.
FORMULA
p_4(x) = (2*sqrt(16-x^2)*Re(3F2(1/2, 1/2, 1/2; 5/6, 7/6; (16-x^2)^3/(108*x^4))))/(Pi^2*x) where 3F2 is the hypergeometric function.
p_4(1) = (2*sqrt(15)*Re(3F2(1/2, 1/2, 1/2; 5/6, 7/6; 125/4)))/Pi^2.
p_4(1) = (1/(2*Pi^2))*sqrt((gamma(1/15)*gamma(2/15)*gamma(4/15)*gamma(8/15))/(5*gamma(7/15)*gamma(11/15)*gamma(13/15)*gamma(14/15))).
Equals Gamma(1/15) * Gamma(2/15) * Gamma(4/15) * Gamma(8/15) / (8*sqrt(5)*Pi^4). - Vaclav Kotesovec, Jun 10 2019
EXAMPLE
0.329933801060064059039790652286952964693683048075834277360260393626...
MAPLE
evalf(GAMMA(1/15)*GAMMA(2/15)*GAMMA(4/15)*GAMMA(8/15) / (8*sqrt(5)*Pi^4), 120); # Vaclav Kotesovec, Jun 10 2019
MATHEMATICA
RealDigits[(2*Sqrt[15]*Re[HypergeometricPFQ[{1/2, 1/2, 1/2}, {5/6, 7/6}, 125/4]])/Pi^2, 10, 104] // First
CROSSREFS
KEYWORD
AUTHOR
Jean-François Alcover, Jul 09 2014
STATUS
approved