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A059031
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Fifth main diagonal of A059026: a(n) = B(n+4,n) = lcm(n+4,n)/(n+4) + lcm(n+4,n)/n - 1 for all n >= 1.
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3
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5, 3, 9, 2, 13, 7, 17, 4, 21, 11, 25, 6, 29, 15, 33, 8, 37, 19, 41, 10, 45, 23, 49, 12, 53, 27, 57, 14, 61, 31, 65, 16, 69, 35, 73, 18, 77, 39, 81, 20, 85, 43, 89, 22, 93, 47, 97, 24, 101, 51, 105, 26, 109, 55, 113, 28, 117, 59, 121, 30, 125, 63, 129, 32, 133, 67
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OFFSET
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1,1
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LINKS
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FORMULA
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a(2n+1) = 4n+5, a(4n+2) = 4n+3, a(4n+4) = 4n+2. - Ralf Stephan, Jun 10 2005
G.f.: -x*(-5-3*x-9*x^2-2*x^3-3*x^4-x^5+x^6) / ( (x-1)^2*(1+x)^2*(x^2+1)^2 ). - R. J. Mathar, Sep 20 2011
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MAPLE
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B := (n, m) -> lcm(n, m)/n + lcm(n, m)/m - 1: seq(B(m+4, m), m=1..90);
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MATHEMATICA
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LinearRecurrence[{0, 0, 0, 2, 0, 0, 0, -1}, {5, 3, 9, 2, 13, 7, 17, 4}, 70] (* Harvey P. Dale, Aug 19 2019 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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