

A072138


Smallest k whose 'Reverse and Subtract' trajectory has a preperiodic part of length n.


2



0, 1, 10, 16, 14, 15, 13, 1011, 1017, 1037, 1027, 1014, 1013, 1028, 100113, 100104, 100145, 100134, 100103, 100112, 100133, 100187, 100114, 100128, 100194, 100107, 100307, 100277, 100413, 100345, 100429, 100215, 100427, 100214, 100433, 100335
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OFFSET

0,3


COMMENTS

'Reverse and Subtract' (cf. A072137) is defined by x > x  reverse(x). For small n the last term of the preperiodic part of the trajectory (cf. A072139) is a palindrome, so this sequence is a weak analog of A033665, which uses 'Reverse and Add'.  1012 is the first n such that last term of the preperiodic part is not palindromic (cf. A072140).


LINKS

Table of n, a(n) for n=0..35.


EXAMPLE

a(8) = 1017, since 1017 is the smallest number whose 'Reverse and Subtract' trajectory has eight preperiodic terms: 1017 > 6084 > 1278 > 7443 > 3996 > 2997 > 4995 > 999.


CROSSREFS

Cf. A033665, A072137, A072139, A072140, A072146.
Sequence in context: A175335 A167788 A072968 * A109891 A104869 A104868
Adjacent sequences: A072135 A072136 A072137 * A072139 A072140 A072141


KEYWORD

base,nonn


AUTHOR

Klaus Brockhaus, Jun 24 2002


STATUS

approved



