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A002968
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Number of pairings {(b(1), c(1)), (b(2), c(2)), ..., (b(n), c(n))} of the first 2n positive integers satisfying b(i) < c(i) and such that the 2n numbers c(i)+b(i) and c(i)-b(i) are all distinct.
(Formerly M4494)
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6
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1, 1, 0, 1, 8, 22, 51, 342, 2609, 16896, 99114, 876579, 8551800, 79595269, 764804085, 8905825760
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OFFSET
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0,5
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COMMENTS
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Huff paper has a typographical error, a(8)=2669. - Sean A. Irvine, Dec 14 2014
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
R. Spira, Noncomplete residue systems, Problem 71-4, SIAM Rev., 14 (1972), 173ff.
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LINKS
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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Better definition and values of a(11)-a(15) from Sean A. Irvine, Dec 14 2014
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STATUS
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approved
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