OFFSET
1,3
COMMENTS
Side length of Prince Rupert's cube: the largest cube that can be passed through a given unit cube (slightly larger than the given cube!).
REFERENCES
Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 8.14, p. 524.
Clifford A. Pickover, The Math Book, Sterling Publishing Co. (New York), 2009, p. 214.
D. J. E. Schrek, Prince Rupert's problem and its extension by Pieter Nieuwland, Scripta Math. 16 (1950), pp. 73-80 and 261-267.
David Wells, Penguin Dictionary of Curious and Interesting Geometry, 1991, p. 195.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Prince Rupert's Cube.
FORMULA
Equals Sum_{k>=0} binomial(2*k,k)/36^k. - Amiram Eldar, Aug 04 2022
EXAMPLE
1.060660171779821286601266543157273558927253906532711...
MATHEMATICA
RealDigits[3 Sqrt[2]/4, 10, 110][[1]] (* Bruno Berselli, Sep 20 2012 *)
PROG
(PARI) sqrt(9/8) \\ Charles R Greathouse IV, Nov 26 2014
(Magma) SetDefaultRealField(RealField(100)); Sqrt(9/8); // G. C. Greubel, Aug 17 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Apr 01 2004
STATUS
approved