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A225758
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Runs of consecutive numbers with the same number and sum of divisors.
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3
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14, 15, 1334, 1335, 1634, 1635, 2685, 2686, 33998, 33999, 42818, 42819, 64665, 64666, 84134, 84135, 109214, 109215, 122073, 122074, 166934, 166935, 289454, 289455, 383594, 383595, 440013, 440014, 544334, 544335, 605985, 605986, 649154, 649155, 655005, 655006
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OFFSET
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1,1
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COMMENTS
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No triple found up to 10^9.
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LINKS
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EXAMPLE
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Sequence begins:
14, 15;
1334, 1335;
1634, 1635;
2685, 2686;
33998, 33999;
etc.
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MATHEMATICA
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sel = Select[Range[1000000], DivisorSigma[0, #] == DivisorSigma[0, #+1] && DivisorSigma[1, #] == DivisorSigma[1, #+1] &]; Union[sel, sel+1]
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CROSSREFS
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Cf. A225756 (same number of divisors), A225757 (same sum of divisors).
Cf. A054004 (first term of every run).
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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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