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A001467
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Denominators of an expansion for Pi.
(Formerly M4464 N1893)
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2
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OFFSET
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0,4
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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Table of n, a(n) for n=0..8.
Mohammad K. Azarian, An Expression for Pi, Problem #870, College Mathematics Journal, Vol. 39, No. 1, January 2008, p. 66. Solution appeared in Vol. 40, No. 1, January 2009, pp. 62-64.
H. E. Salzer, The approximation of numbers as sums of reciprocals, Amer. Math. Monthly, 54 (1947), 135-142.
J. W. Wrench, Jr., Letter to N. J. A. Sloane, Mar 27 1974
Index entries for sequences related to the number Pi
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FORMULA
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Numerators are 1.
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EXAMPLE
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a(4) = -791 since Pi - (1/1) - (1/1) - (1/1) - (1/7) = -0.001264489... is closer to 1/(-791) = -0.001264222... than to 1/(-790) = -0.0012658228...
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PROG
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(PARI) x=Pi; for(k=0, 8, if(x<1, d=round(1/x), d=1); x=x-1/d; print(d, ", ")) \\ Jaume Oliver Lafont, Feb 21 2009
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CROSSREFS
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Cf. A001466, A014013, A073422.
Sequence in context: A182282 A171245 A014013 * A278438 A279120 A047788
Adjacent sequences: A001464 A001465 A001466 * A001468 A001469 A001470
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KEYWORD
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sign,frac
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AUTHOR
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N. J. A. Sloane
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EXTENSIONS
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Edited by Henry Bottomley, Jul 30 2002
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STATUS
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approved
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