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A046202
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Distinct numbers in the triangle of denominators in Leibniz's Harmonic Triangle.
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2
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1, 2, 3, 6, 4, 12, 5, 20, 30, 60, 7, 42, 105, 140, 8, 56, 168, 280, 9, 72, 252, 504, 630, 10, 90, 360, 840, 1260, 11, 110, 495, 1320, 2310, 2772, 132, 660, 1980, 3960, 5544, 13, 156, 858, 2860, 6435, 10296, 12012, 14, 182, 1092, 4004, 10010, 18018, 24024, 15
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OFFSET
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1,2
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COMMENTS
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Numbers in the order in which they appear in Leibniz's Harmonic Triangle (A003506). This sequence is a permutation of the natural numbers. - Robert G. Wilson v, Jun 12 2014
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REFERENCES
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L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25.
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LINKS
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EXAMPLE
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1/1; 1/2, 1/2; 1/3, 1/6, 1/3; 1/4, 1/12, 1/12, 1/4; 1/5, 1/20, 1/30, 1/20, 1/5; ...
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MATHEMATICA
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t[n_, k_] := Denominator[n!*k!/(n + k + 1)!]; DeleteDuplicates@ Flatten@ Table[t[n - k, k], {n, 0, 14}, {k, 0, n/2}] (* Robert G. Wilson v, Jun 12 2014 *)
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CROSSREFS
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KEYWORD
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tabf,nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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