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A067580
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a(n) = Product_{i=2..n} A001222(i) * Sum_{i=2..n} 1/A001222(i).
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1
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1, 2, 5, 7, 16, 20, 64, 140, 304, 352, 1104, 1248, 2640, 5568, 22848, 25152, 77760, 84672, 260928, 542592, 1126656, 1209600, 4921344, 10174464, 21012480, 64364544, 197074944, 209018880, 639000576, 674832384, 3409993728
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internal format)
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OFFSET
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2,2
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LINKS
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Robert Israel, Table of n, a(n) for n = 2..2374
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EXAMPLE
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A001222(2) = 1, A001222(3) = 1, A001222(4) = 2, so a(4) = (1*1*2)*(1+1+1/2)=5. - Robert Israel, Dec 29 2015
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MAPLE
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P:= 1: S:= 0:
for n from 2 to 100 do
b:= numtheory:-bigomega(n);
P:= P*b; S:= S + 1/b;
A[n]:= P*S;
od:
seq(A[n], n=2..100); # Robert Israel, Dec 29 2015
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MATHEMATICA
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Table[Product[PrimeOmega[k], {k, 2, n}] * Sum[1/PrimeOmega[k], {k, 2, n}], {n, 2, 50}] (* Vaclav Kotesovec, Dec 30 2015 *)
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CROSSREFS
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Cf. A001222.
Sequence in context: A032045 A207035 A322440 * A325210 A181447 A082088
Adjacent sequences: A067577 A067578 A067579 * A067581 A067582 A067583
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KEYWORD
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nonn
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AUTHOR
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Benoit Cloitre, Jan 30 2002
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EXTENSIONS
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Name and offset corrected by Robert Israel, Dec 29 2015
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STATUS
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approved
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