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A074242 Numbers n such that sigma(n+1) = reverse(sigma(n)). 1
5602, 42346, 184650339, 356930335 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..4.

EXAMPLE

sigma(5602 + 1) = 6048 = reverse(8406) = reverse(sigma(5602)), so 5602 is a term of the sequence.

MATHEMATICA

Do[ If[FromDigits[Reverse[IntegerDigits[DivisorSigma[1, n]]]] == DivisorSigma[1, n + 1], Print[n]], {n, 1, 10^7}]

CROSSREFS

Sequence in context: A109565 A126784 A071813 * A032737 A237507 A198164

Adjacent sequences:  A074239 A074240 A074241 * A074243 A074244 A074245

KEYWORD

base,more,nonn

AUTHOR

Joseph L. Pe, Sep 19 2002

EXTENSIONS

a(3)-a(4) from Donovan Johnson, Feb 01 2009

STATUS

approved

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Last modified August 2 02:25 EDT 2014. Contains 245138 sequences.