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A073142
List of smallest solutions for some k of x = f^k(x), n <> f^j(n) for j < k, where f: m -> |m - reverse(m)|.
3
0, 2178, 11436678, 108811891188, 118722683079
OFFSET
1,2
COMMENTS
In the definition, j can be restricted to proper divisors of k. A073143 gives the corresponding values of k. A073144(n) gives the smallest m such that the 'Reverse and Subtract' trajectory of m leads to a(n). Presumably a(6) = 1186781188132188 with k = 17.
EXAMPLE
a(3) = 11436678 is the smallest solution of x = f^14(x) and there is no k such that x = f^k(x) has a smallest solution between a(2) = 2178 and a(3).
KEYWORD
base,more,nonn
AUTHOR
Klaus Brockhaus, Jul 17 2002
EXTENSIONS
Offset changed by N. J. A. Sloane, Dec 01 2007
STATUS
approved