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A007736 Period of repeating digits of 1/n in base 5. 3
1, 1, 2, 1, 1, 2, 6, 2, 6, 1, 5, 2, 4, 6, 2, 4, 16, 6, 9, 1, 6, 5, 22, 2, 1, 4, 18, 6, 14, 2, 3, 8, 10, 16, 6, 6, 36, 9, 4, 2, 20, 6, 42, 5, 6, 22, 46, 4, 42, 1, 16, 4, 52, 18, 5, 6, 18, 14, 29, 2, 30, 3, 6, 16, 4, 10, 22, 16, 22, 6, 5, 6, 72, 36, 2, 9, 30, 4, 39, 4, 54, 20, 82, 6, 16, 42, 14, 10, 44 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

Index entries for sequences related to decimal expansion of 1/n

MATHEMATICA

f[n_] := MultiplicativeOrder[5, n/(5^IntegerExponent[n, 5])]; Array[f, 80] (* Robert G. Wilson v, Jun 10 2011 *)

Table[Length[RealDigits[1/n, 5][[1, 1]]], {n, 90}]/.(0->1) (* Harvey P. Dale, Dec 28 2016 *)

PROG

(PARI) A007736(n, bas)={ local(p) ; for(sp=2, 1000000, for(s=1, sp-1, p=sp-s ; if( ((bas^p-1)*bas^s) % n == 0, return(p) ; ) ; ) ; ) ; return(-1) ; } { for(n=1, 100, print(n, " ", A007736(n, 5)) ; ) ; } - R. J. Mathar, Aug 30 2006

(PARI) a(n)=znorder(Mod(5, n/5^valuation(n, 5))) \\ Charles R Greathouse IV, Jun 10 2011

CROSSREFS

Sequence in context: A123218 A298608 A327815 * A107042 A134830 A319031

Adjacent sequences:  A007733 A007734 A007735 * A007737 A007738 A007739

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com), David W. Wilson

STATUS

approved

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Last modified October 18 15:41 EDT 2019. Contains 328162 sequences. (Running on oeis4.)