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A073500
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Numbers n such that sigma(n) = sigma(n+1)+sigma(n-1).
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7
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954, 1300, 11142, 38214, 89484, 152154, 167784, 254136, 303280, 473316, 574716, 813920, 918080, 1307022, 2008360, 3676242, 9878244, 10368512, 12548754, 19411480, 22493262, 42413484, 77766486, 81513816, 157874000, 240828972
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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s1 = s2 = s3 = 0; Do[ s1 = s2; s2 = s3; s3 = DivisorSigma[1, n]; If[ s2 == s1 + s3, Print[n - 1]], {n, 1, 10^8}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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