OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Yff Conjecture
EXAMPLE
1.4093562703546197036...
MATHEMATICA
f[a_] := a^2*(Pi - 2*a) - 8*ArcCot[2*Cot[a] - Cot[2*a]]^3; RealDigits[ a /. FindRoot[f'[a] == 0, {a, 3/2}, WorkingPrecision -> 110], 10, 105] // First (* Jean-François Alcover, Feb 07 2013, after Eric W. Weisstein *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Sep 26 2007
STATUS
approved