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A070310
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Numbers n such that the sum of its aliquot parts and the number of its divisors are both perfect numbers.
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0
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OFFSET
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1,1
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COMMENTS
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LINKS
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MATHEMATICA
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p = {6, 28, 496, 8128, 33550336}; Do[a = Divisors[n]; If[ Position[p, Plus @@ Drop[a, -1]] != {} && Position[p, Length[a]] != {}, Print[n]], {n, 1, 10^7}]
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PROG
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(PARI) {for(n=1, 10^8, d=numdiv(n); if(d==sigma(d)-d, s=sigma(n)-n; if(s==sigma(s)-s, print1(n, ", "))))}
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CROSSREFS
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KEYWORD
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more,nonn,bref
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AUTHOR
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EXTENSIONS
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No further terms below 10^8. Is the sequence complete? - Klaus Brockhaus, May 17 2002
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STATUS
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approved
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