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A045895
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Period length of pairs (a,b) where a has period 2n-2 and b has period n.
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4
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0, 2, 12, 12, 40, 30, 84, 56, 144, 90, 220, 132, 312, 182, 420, 240, 544, 306, 684, 380, 840, 462, 1012, 552, 1200, 650, 1404, 756, 1624, 870, 1860, 992, 2112, 1122, 2380, 1260, 2664, 1406, 2964, 1560
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = n*(n-1) for n even.
a(n) = 2*n*(n-1) for n odd.
a(n) = lcm(2*n-2, n).
Sum_{n>=2} 1/a(n) = (log(2)+1)/2. (End)
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MATHEMATICA
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Table[ LCM[ 2*n-2, n ], {n, 40} ]
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PROG
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(PARI) for(n=1, 50, print1(lcm(2*n-2, n), ", ")) \\ G. C. Greubel, Jun 15 2018
(Magma) [Lcm(2*n-2, n): n in [1..50]]; // G. C. Greubel, Jun 15 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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