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 A036275 The periodic part of the decimal expansion of 1/n. Any initial 0's are to be placed at end of cycle. 19
 0, 0, 3, 0, 0, 6, 142857, 0, 1, 0, 90, 3, 769230, 714285, 6, 0, 5882352941176470, 5, 526315789473684210, 0, 476190, 45, 4347826086956521739130, 6, 0, 384615, 370, 571428, 3448275862068965517241379310, 3, 322580645161290, 0, 30, 2941176470588235, 285714, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(n) = 0 iff n = 2^i*5^j (A003592). - Jon Perry, Nov 19 2014 LINKS Philippe Guglielmetti, Table of n, a(n) for n = 1..1001 (first 500 terms from T. D. Noe) EXAMPLE 1/28 = .03571428571428571428571428571428571428571... and digit-cycle is 571428, so a(28)=571428. MAPLE isCycl := proc(n) local ifa, i ; if n <= 2 then RETURN(false) ; fi ; ifa := ifactors(n)[2] ; for i from 1 to nops(ifa) do if op(1, op(i, ifa)) <> 2 and op(1, op(i, ifa)) <> 5 then RETURN(true) ; fi ; od ; RETURN(false) ; end: A036275 := proc(n) local ifa, sh, lpow, mpow, r ; if not isCycl(n) then RETURN(0) ; else lpow:=1 ; while true do for mpow from lpow-1 to 0 by -1 do if (10^lpow-10^mpow) mod n =0 then r := (10^lpow-10^mpow)/n ; r := r mod (10^(lpow-mpow)-1) ; while r*10 < 10^(lpow-mpow) do r := 10*r ; od ; RETURN(r) ; fi ; od ; lpow := lpow+1 ; od ; fi ; end: for n from 1 to 60 do printf("%d %d ", n, A036275(n)) ; od ; # R. J. Mathar, Oct 19 2006 MATHEMATICA fc[n_]:=Block[{q=RealDigits[1/n][[1, -1]]}, If[IntegerQ[q], 0, While[First[q]==0, q=RotateLeft[q]]; FromDigits[q]]]; Table[fc[n], {n, 36}] (* Ray Chandler, Nov 19 2014, corrected Jun 27 2017 *) Table[FromDigits[FindTransientRepeat[RealDigits[1/n, 10, 120][[1]], 3] [[2]]], {n, 40}] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 12 2019 *) CROSSREFS Cf. A007732, A051626, A036275, A002371, A048595, A006883, A007498, A007615, A040017, A051627. See also A060282, A060283, A060251. A051628 is length of preamble. Sequence in context: A110620 A270392 A060284 * A131436 A046765 A046777 Adjacent sequences:  A036272 A036273 A036274 * A036276 A036277 A036278 KEYWORD base,nonn,easy,nice AUTHOR EXTENSIONS Corrected and extended by N. J. A. Sloane Corrected a(92), a(208), a(248), a(328), a(352) and a(488) which missed a trailing zero (see the table). - Philippe Guglielmetti, Jun 20 2017 STATUS approved

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Last modified October 15 11:01 EDT 2019. Contains 328026 sequences. (Running on oeis4.)