2,1

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 (blekraj(AT)yahoo.com), 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,... [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 30 2009]

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

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

We have the a(4)=6-digit 4-transposable number 410256=4*102564.

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

Sequence in context: A138336 A166630 A154920 this_sequence A128858 A141782 A161813

Adjacent sequences: A094221 A094222 A094223 this_sequence A094225 A094226 A094227

fini,nonn,base

Lekraj Beedassy (blekraj(AT)yahoo.com), May 28 2004