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A371211
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Number of ordered factorizations of n into factors > 3.
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4
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1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 3, 2, 1, 1, 3, 1, 3, 1, 3, 1, 1, 3, 4, 1, 1, 1, 5, 1, 3, 1, 3, 3, 1, 1, 5, 2, 3, 1, 3, 1, 3, 3, 5, 1, 1, 1, 7, 1, 1, 3, 5, 3, 3, 1, 3, 1, 5, 1, 7, 1, 1, 3, 3, 3, 3, 1, 10, 2, 1, 1, 7, 3, 1, 1, 5, 1
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OFFSET
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1,16
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LINKS
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FORMULA
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a(1) = 1; a(n) = Sum_{d|n, n/d > 3} a(d).
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EXAMPLE
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a(20) = 3: 20 = 4*5 = 5*4.
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MATHEMATICA
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a[n_] := a[n] = If[n == 1, n, Sum[If[n/d > 3, a[d], 0], {d, Divisors[n]}]]; Table[a[n], {n, 1, 89}]
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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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