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A157756 Integers n such that by splitting their digits in two equal parts, the difference between the square of the first part and the second part eventually reaches 0 by iterating the process. If length is odd, split (length+1)/2 , (length-1)/2 0
0, 11, 24, 39, 45, 51, 74, 97, 103, 150, 151, 155, 220, 224, 225, 229, 230, 234, 240, 290 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Example 3480 belongs to the sequence, because 34^2-80 = 1076 --> 10^2-76 = 24 --> 2^2-4 = 0

Nice zoomable picture of the directed graph (up to 1000) :

http://vargo.chez.com/upto1000.jpg

or if you prefer a GIF :

http://vargo.chez.com/upto1000.gif

The terms up to 11000 :

http://vargo.chez.com/upto11000.txt

LINKS

Table of n, a(n) for n=1..20.

CROSSREFS

Sequence in context: A213991 A269100 A213062 * A061043 A098603 A274620

Adjacent sequences:  A157753 A157754 A157755 * A157757 A157758 A157759

KEYWORD

base,easy,nonn

AUTHOR

Jean-Marc Falcoz, Mar 06 2009

STATUS

approved

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Last modified July 20 15:59 EDT 2019. Contains 325185 sequences. (Running on oeis4.)