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 A166320 Numbers which are proper divisors of the number obtained by cyclic right-shift by 2 positions. 0
 142857, 153846, 190476, 230769, 238095, 307692, 142857142857, 153846153846, 190476190476, 230769230769, 238095238095, 307692307692, 1176470588235294, 100250626566416040, 102756892230576441, 105263157894736842, 107769423558897243 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers which are invariant under the cyclic shift are not in the sequence, because they are not proper divisors of themselves. LINKS EXAMPLE 153846 is a proper divisor of 461538, obtained by moving the two least significant digits "46" to the front. 230769 is a proper divisor of 692307, obtained by moving the least significant digits "69" to the front. MAPLE cycShft := proc(n) local L, Ls ; if n < 100 then n; else L := convert(n, base, 10) ; Ls := [op(3..nops(L), L), op(1..2, L)] ; add(op(i, Ls)*10^(i-1), i=1..nops(Ls)) ; end if; end proc: isA166320 := proc(n) local c; c := cycShft(n) ; return c mod n = 0 and c <> n ; end: for n from 100 do if isA166320(n) then printf("%d, \n", n) ; fi; od: # R. J. Mathar, Oct 14 2009 PROG (PARI) { genupto(m) = R = []; for(k=2, 9, for(a=10*k, 99, d = 100*k - 1; q = znorder( Mod(10, d/gcd(d, a)) ); forstep(z=q, m, q, R = concat(R, [(10^z-1)*a/d]); ); ); ); vecsort(R, , 8) } \\ generate all terms of length up to m. Max Alekseyev, Jan 22 2012 CROSSREFS Sequence in context: A086999 A175694 A023089 * A101202 A323711 A306265 Adjacent sequences:  A166317 A166318 A166319 * A166321 A166322 A166323 KEYWORD nonn,base AUTHOR Claudio Meller, Oct 11 2009 EXTENSIONS keyword:base added by R. J. Mathar, Oct 14 2009 Corrected my number typo in the examples - R. J. Mathar, Oct 23 2009 More terms from Sean A. Irvine, Feb 25 2010 More terms from Max Alekseyev, Jan 22 2012 STATUS approved

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Last modified October 18 12:18 EDT 2019. Contains 328160 sequences. (Running on oeis4.)