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A322607
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Numbers that can be expressed as the ratio between the product and the sum of consecutive squarefree numbers starting from 1.
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2
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1, 3080, 350350, 61850250, 17823180375, 6871260396000, 88909822914869880000, 2746644314348614680000, 2980109081068246927800000, 9638057975990853416623724908800000, 424217819372970387341691005411520000, 51912228216508515627667235880347808000000, 152157812632066726080765311397008321568000000
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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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EXAMPLE
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1 is a term because 1/1 = (1*2*3)/(1+2+3) = 1.
3080 is a term because (1*2*3*5*6*7*10*11)/(1+2+3+5+6+7+10+11) = 138600/45 = 3080.
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MAPLE
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with(numtheory): P:=proc(q) local a, b, c, n; a:=1; b:=0; c:=[];
for n from 1 to q do if issqrfree(n) then a:=a*n; b:=b+n;
if frac(a/b)=0 then if n>1 then c:=[op(c), a/b];
fi; fi; fi; od; op(c); end: P(60);
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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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