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A074242
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Numbers n such that sigma(n+1) = reverse(sigma(n)).
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1
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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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EXAMPLE
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sigma(5602 + 1) = 6048 = reverse(8406) = reverse(sigma(5602)), so 5602 is a term of the sequence.
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MATHEMATICA
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Do[ If[FromDigits[Reverse[IntegerDigits[DivisorSigma[1, n]]]] == DivisorSigma[1, n + 1], Print[n]], {n, 1, 10^7}]
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PROG
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(PARI) isok(n) = digits(sigma(n+1)) == Vecrev(digits(sigma(n))); \\ Michel Marcus, Jun 26 2015
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CROSSREFS
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Cf. A028980 (sigma(n) = reverse(sigma(n))).
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KEYWORD
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base,more,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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