OFFSET
0,1
COMMENTS
The return probability equals unity minus this constant. The expected number of visits to the origin is the inverse of this constant.
The escape probability for the hcp lattice also equals this constant. The escape probability for the diamond lattice is 3/4 times this constant.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..10000
Shunya Ishioka and Masahiro Koiwa, Random walks on diamond and hexagonal close packed lattices, Phil. Mag. A, 37 (1978), 517-533.
G. L. Montet, Integral methods in the calculation of correlation factors in diffusion, Phys. Rev. B 7 (1973), 650-662.
FORMULA
Equals 2^(14/3)*Pi^4/(9*Gamma(1/3)^6).
EXAMPLE
0.74368176349535122890496981936537648...
MATHEMATICA
RealDigits[2^(14/3)*Pi^4/(9*Gamma[1/3]^6), 10, 100][[1]] (* G. C. Greubel, Oct 26 2018 *)
PROG
(PARI) 2^(14/3)*Pi^4/(9*gamma(1/3)^6) \\ Altug Alkan, Apr 09 2018
(Magma) SetDefaultRealField(RealField(100)); R:= RealField(); 2^(14/3)*Pi(R)^4/(9*Gamma(1/3)^6); // G. C. Greubel, Oct 26 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Andrey Zabolotskiy, Oct 03 2017
STATUS
approved