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A094224 Number of digits in the least n-transposable number. 4
18, 28, 6, 6, 58, 22, 13, 44 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

A k-transposable number, where 2<=k<=9, is one which is equal to k times the number whose digits are a cyclic permutation of its leftmost digit to the right.

Corresponds to the least value m+1 such that 10*n-1 |10^m - n, or merely to the order of 10 mod (10*n-1). - Lekraj Beedassy, Aug 21 2004

This could be considered the start of the b=10th row in the array defined by T(b,n) = the order of b mod (b*n-1), A002326 in row 2, A003572 in row 3, A003574 in row 4. With this definition, the sequence continues 18, 28, 6, 42, 58, 22, 13, 44, 2, 108, 48, 21, 46, 148, 13, 78, 178, 6, ... - R. J. Mathar, Mar 30 2009

REFERENCES

P. Tougne, "Jeux Mathematiques", Prob. 8, pp. 104 and 107 Aug. 1982 issue of Pour La Science (French edition of 'Scientific American'), Paris.

LINKS

Table of n, a(n) for n=2..9.

K. Matthews, Finding the order a (mod m)

EXAMPLE

We have the a(4)=6-digit 4-transposable number 410256=4*102564, and the a(5)=6-digit 5-transposable number 714285=5*142857.

MAPLE

A094224b := proc(n, b) numtheory[order](b, b*n-1) ; end: A094224 := proc(n) A094224b(n, 10) ; end: seq(A094224(n), n=2..9) ; # R. J. Mathar, Mar 30 2009

CROSSREFS

Cf. A092697 (value of the least n-transposable number).

Sequence in context: A138336 A166630 A154920 * A128858 A141782 A093648

Adjacent sequences:  A094221 A094222 A094223 * A094225 A094226 A094227

KEYWORD

fini,full,nonn,base

AUTHOR

Lekraj Beedassy, May 28 2004

STATUS

approved

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Last modified December 11 18:19 EST 2019. Contains 329925 sequences. (Running on oeis4.)