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Search: id:A122180
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| A122180 |
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Number of ways to write n as n = x*y*z with 1<x<y<z<n. |
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+0
3
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| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 3, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 3, 0, 0, 0, 1, 0, 3, 0, 0, 0, 0, 0, 4, 0, 0, 0, 1, 0, 1, 0, 1, 1
(list; graph; listen)
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OFFSET
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1,48
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COMMENT
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x,y,z are distinct proper factors of n. See A122181 for n such that a(n) > 0.
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EXAMPLE
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a(48) = 2 because 48 = 2*3*8 = 2*4*6, two products of three distinct proper factors of 48.
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PROGRAM
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(PARI) for(n=1, 105, t=0; for(x=2, n-1, for(y=x+1, n-1, for(z=y+1, n-1, if(x*y*z==n, t++)))); print1(t, ", "))
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CROSSREFS
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Cf. A034836, A088432, A088433, A088434, A122179, A122181.
Sequence in context: A101638 A070141 A088722 this_sequence A033772 A086015 A086012
Adjacent sequences: A122177 A122178 A122179 this_sequence A122181 A122182 A122183
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KEYWORD
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nonn
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AUTHOR
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Rick L. Shepherd (rshepherd2(AT)hotmail.com), Aug 23 2006
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