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%I #25 Aug 11 2024 14:41:34
%S 0,3,0,6,2,6,16,18,22,28,15,3,5,21,46,13,58,60,33,35,8,13,41,44,96,4,
%T 34,53,108,112,42,130,8,46,148,75,78,81,166,43,178,180,95,192,98,99,
%U 30,222,113,228,232,7,30,50,256,262,268,5,69,28,141,146,153,155,312,79,110
%N Length of least repunit which is a multiple of the n-th prime, or 0 if no such multiple exists.
%C If prime(n) = p then a(n) is a divisor of p-1. - _Amarnath Murthy_, Nov 11 2002
%H Michael De Vlieger, <a href="/A071126/b071126.txt">Table of n, a(n) for n = 1..1000</a>
%H P. De Geest, <a href="https://www.worldofnumbers.com/repunits.htm">Repunits and Their Factors</a>
%H Amarnath Murthy, <a href="http://rxiv.org/abs/1403.0524">On the divisors of Smarandache Unary Sequence</a>, Smarandache Notions Journal, Vol. 11, 2000.
%H A. A. A. Steward, <a href="/A071126/a071126_1.txt">Factorization of Repunits[up to R(196)]</a>. Cached copy, Sep 25 2000.
%H Michael De Vlieger, <a href="/A071126/a071126.txt">Records and positions in first 1000 terms of A071126</a>
%e The 13th prime, 41, divides the repunit 11111, the smallest among all R(5k) which are multiples of 41.
%t Table[Function[p, If[Divisible[10, p], 0, k = {1}; While[! Divisible[ FromDigits@ k, p], AppendTo[k, 1]]; Length@ k]]@ Prime@ n, {n, 67}] (* _Michael De Vlieger_, May 20 2017 *)
%Y Number of 1's in A077573(n).
%Y Cf. A000042. Apart from a(2), identical to A002371.
%K nonn
%O 1,2
%A _Lekraj Beedassy_, May 28 2002
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