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A141848
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Decimal expansion of the Pell constant.
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3
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5, 8, 0, 5, 7, 7, 5, 5, 8, 2, 0, 4, 8, 9, 2, 4, 0, 2, 2, 9, 0, 0, 4, 3, 8, 9, 2, 2, 9, 7, 0, 2, 5, 7, 4, 7, 7, 6, 6, 0, 4, 6, 7, 6, 5, 6, 0, 7, 3, 3, 3, 2, 5, 0, 9, 1, 9, 5, 5, 0, 0, 8, 3, 3, 6, 8, 2, 2, 7, 9, 4, 9, 1, 2, 7, 2, 9, 0, 8, 0, 6, 0, 8, 9, 9, 7, 6, 7, 5, 4, 5, 2, 5, 7, 6, 1, 8, 0, 4, 4, 9, 7, 1, 4, 1
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OFFSET
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0,1
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REFERENCES
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Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, p. 119.
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LINKS
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Table of n, a(n) for n=0..104.
Wieb Bosma and Peter Stevenhagen, Density computations for real quadratic units, Mathematics of Computation, Vol. 65, No. 215 (1996), pp. 1327-1337.
Peter Stevenhagen, The number of real quadratic fields having units of negative norm, Experimental Mathematics, Vol. 2, No. 2 (1993), pp. 121-136; alternative link.
Peter Stevenhagen, A density conjecture for the negative Pell equation, in: W. Bosma, A. van der Poorten (eds.), Computational Algebra and Number Theory, Springer, Dordrecht, 1995, pp. 187-200.
Eric Weisstein's World of Mathematics, Pell Constant.
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FORMULA
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Equals 1 - QPochhammer(1/2, 1/4).
Equals 1 - Product_{n>=0} (1 - 1/2^(2*n+1)). - Jean-François Alcover, May 20 2014
Equals 1 - A132020. - Amiram Eldar, Apr 11 2022
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EXAMPLE
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0.58057755820489240229...
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MATHEMATICA
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RealDigits[1-QPochhammer[1/2, 1/4], 10, 120][[1]] (* Harvey P. Dale, Dec 17 2011 *)
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CROSSREFS
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Cf. A132020.
Sequence in context: A198360 A153420 A193505 * A349398 A349397 A140249
Adjacent sequences: A141845 A141846 A141847 * A141849 A141850 A141851
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KEYWORD
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nonn,cons
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AUTHOR
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Eric W. Weisstein, Jul 11 2008
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STATUS
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approved
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