A178505 - OEIS

%I #18 Sep 15 2022 08:05:27

%S 3,142857,1,9,76923,588235294117647,52631578947368421,47619,

%T 434782608695652173913,37,344827586206896551724137931,32258064516129,

%U 3,27,25641,2439,23255813953488372093

%N Decimal form of the period of 1/n for n such that gcd(n,10)=1. Leading zeros are suppressed.

%C The numbers n are A045572, and the corresponding periods are A002329.

%H Ray Chandler, <a href="/A178505/b178505.txt">Table of n, a(n) for n = 1..406</a> (terms up to 1000 digits)

%F a(n) = A060284(A045572(n+1)). [_R. J. Mathar_, Jun 26 2010]

%e 3 is in the sequence because 1/3 = 0.3333...

%e 142857 is in the sequence because 1/7 = 0.142857 142857 ...

%e 1 is in the sequence because 1/9 = 0.1111....

%p with(numtheory): nn:= 100: T:=array(1..nn):k:=1: U:=array(1..nn):k:=1: for n from 2 to 200 do:x:=1/n:for p from 1 to 200 while(irem(10^p,n)<>1 or gcd(n,10)<> 1) do:od: if irem(10^p,n) = 1 and gcd(n,10) = 1 then y:=floor(x*10^p): T[k]:=y: U[k]:=n : k:=k+1:else fi:od:print(T):

%Y Cf. A002329, A036275, A045572, A060284.

%K nonn,base

%O 1,1

%A _Michel Lagneau_, May 29 2010

%E Name corrected by _T. D. Noe_, Jul 07 2010