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A135386
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Mersenne composites A065341 with 4 or more prime factors.
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1
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OFFSET
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1,1
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LINKS
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MAPLE
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i := 2^(ithprime(n))-1:
if (nops(numtheory[factorset](i)) > 3) then
RETURN (i)
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MATHEMATICA
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k = {}; Do[If[ ! PrimeQ[2^Prime[n] - 1], c = FactorInteger[2^Prime[n] - 1]; d = Length[c]; If[d >3, AppendTo[k, 2^Prime[n] - 1]]], {n, 1, 40}]; k
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CROSSREFS
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KEYWORD
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nonn,bref
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AUTHOR
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STATUS
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approved
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