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A343392
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Decimal expansion of 2*Pi*sqrt(2).
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2
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8, 8, 8, 5, 7, 6, 5, 8, 7, 6, 3, 1, 6, 7, 3, 2, 4, 9, 4, 0, 3, 1, 7, 6, 1, 9, 8, 0, 1, 2, 1, 3, 8, 7, 3, 9, 7, 2, 2, 9, 2, 4, 3, 3, 7, 8, 7, 5, 1, 3, 8, 0, 4, 4, 6, 1, 7, 0, 7, 9, 1, 2, 1, 3, 9, 1, 2, 8, 6, 9, 5, 8, 6, 1, 9, 8, 9, 4, 7, 8, 2, 1, 1, 5, 0, 6, 5, 3, 8, 6, 9
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OFFSET
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1,1
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COMMENTS
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Circumference of the circumcircle of the square whose sides = 2.
Hypotenuse of the right isosceles triangle with the two legs = 2*Pi.
Perimeter of the closed curve with implicit Cartesian equation x^2 + y^2 = abs(x) + abs(y). This curve in the first quadrant is the half-circle with equation (x-1/2)^2 + (y-1/2)^2 = 1/2, hence, the curve is the union of 4 identical half-circles with diameter = sqrt(2) obtained by symmetries. (See link Curve.)
S. Ramanujan produced a curious approximation to 2*Pi*sqrt(2) by dividing 99^2 by 1103 (see link Prime Curios! and A343393).
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LINKS
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FORMULA
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EXAMPLE
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8.88576587631673249403176198012138739722924337875138044617
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MAPLE
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evalf(2*Pi*sqrt(2), 120);
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MATHEMATICA
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RealDigits[2*Sqrt[2]*Pi, 10, 100][[1]] (* Amiram Eldar, Apr 13 2021 *)
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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