OFFSET
1,3
FORMULA
(116 - 8 Sqrt[2] - 20 Sqrt[5] + 140 ArcCsch[2] - 40 ArcSinh[1] + 80 ArcSinh[2] + Log[32] + 10 Log[-1 + Sqrt[5]] - 15 Log[123 + 55 Sqrt[5]]) / 120
EXAMPLE
1.0881382498612540260133800398822187615937033186594483235371...
MATHEMATICA
d[x1_, y1_, x2_, y2_] := Sqrt[ (x1-x2)^2+(y1-y2)^2 ]
Integrate[ d[x1, y1, x2, y2], {x1, -1, 0}, {x2, 0, 1}, {y1, 0, 1}, {y2, 0, 1} ]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Richard C. Schroeppel and Michael Kleber, Mar 05 2008
STATUS
approved