OFFSET
0,1
LINKS
Shu-Chiuan Chang and Robert Shrock, Some Exact Results for Spanning Trees on Lattices., Discrete Math., J. Phys. A: Math. Gen. 39, 5653-5658 (2006).
FORMULA
C/Pi + (1/4)*log(3-2*sqrt(2)) + (1/Pi)*integral_{0..3+2*sqrt(2)} arctan(t)/t dt, where C is Catalan's constant.
EXAMPLE
0.786684275378832179121657989494695380551170816578...
MATHEMATICA
z[br] = Catalan/Pi + (1/4)*Log[3-2*Sqrt[2]] + (1/Pi)*Integrate[ArcTan[t]/t, {t, 0, 3+2*Sqrt[2]}]; RealDigits[N[Re[z[br]], 103]] // First
CROSSREFS
KEYWORD
AUTHOR
Jean-François Alcover, Jul 31 2014
STATUS
approved