

A071126


Length of least repunit which is a multiple of the nth prime, or 0 if no such multiple exists.


7



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, 34, 53, 108, 112, 42, 130, 8, 46, 148, 75, 78, 81, 166, 43, 178, 180, 95, 192, 98, 99, 30, 222, 113, 228, 232, 7, 30, 50, 256, 262, 268, 5, 69, 28, 141, 146, 153, 155, 312, 79, 110
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OFFSET

1,2


COMMENTS

If prime(n) = p then a(n) is a divisor of p1.  Amarnath Murthy, Nov 11 2002


LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..1000
P. De Geest, Repunits and Their Factors
Amarnath Murthy, On the divisors of Smarandache Unary Sequence, Smarandache Notions Journal, Vol. 11, 2000.
A. A. A. Steward, Factorization of Repunits[up to R(196)]. Cached copy, Sep 25 2000.
Michael De Vlieger, Records and positions in first 1000 terms of A071126


EXAMPLE

The 13th prime, 41, divides the repunit 11111, the smallest among all R(5k) which are multiples of 41.


MATHEMATICA

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 *)


CROSSREFS

Number of 1's in A077573(n).
Cf. A000042. Apart from a(2), identical to A002371.
Sequence in context: A334950 A171419 A077574 * A077187 A011079 A334874
Adjacent sequences: A071123 A071124 A071125 * A071127 A071128 A071129


KEYWORD

nonn


AUTHOR

Lekraj Beedassy, May 28 2002


STATUS

approved



