login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified November 26 14:56 EST 2014. Contains 250079 sequences.