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A144504
3-transposable numbers.
1
142857, 285714, 142857142857, 285714285714, 142857142857142857, 285714285714285714, 142857142857142857142857, 285714285714285714285714, 142857142857142857142857142857, 285714285714285714285714285714, 142857142857142857142857142857142857
OFFSET
1,1
COMMENTS
A positive integer x is called k-transposable if when the leftmost digit is moved into the units place, the result is equal to kx.
A number is 1-transposable iff its digits are all the same.
Kahan shows that if k>1 then k must be 3 and the only solutions are concatenations of copies of either 142857 or 285714, as given in this sequence, which therefore lists all k-transposable numbers with k>1.
LINKS
S. Kahan, k-transposable integers, Math. Mag., 49 (1976), 27-28.
CROSSREFS
Sequence in context: A101202 A323711 A306265 * A344436 A146754 A180340
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Dec 14 2008
STATUS
approved