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A004285 Least positive multiple of n written in base 5 using only 0 and 1. 2
1, 11, 11, 1111, 10, 11, 1001, 10111, 1001, 110, 11111, 1111, 101, 1001, 110, 10111, 101111, 1001, 110111, 11110, 1001, 101011, 100101, 11111111, 100, 101, 11011, 11011, 1000011, 110, 111, 110101, 1011101, 111001, 10010, 11011, 101011, 111001, 1111, 101110, 10111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

N:= 100: # to get a(1) .. a(N)

S:= [[1, 1]]:

A[1]:= 1:

Todo:= {$2..N}:

count:= 1:

for d from 2 while count < N do

  S:= map(t -> ([5*t[1], 10*t[2]], [5*t[1]+1, 10*t[2]+1]), S);

  for p in S do

    s:= p[1];

    Ts:= select(t -> s mod t = 0, Todo);

    Todo:= Todo minus Ts;

    count:= count + nops(Ts);

    for m in Ts do

         A[m]:= p[2];

    od

  od;

od:

seq(A[n], n=1..N); # Robert Israel, Dec 28 2015

PROG

(PARI) a(n) = {k=1; while (vecmax(digits(k*n, 5)) != 1, k++); subst(Pol(digits(k*n, 5)), x, 10); } \\ Michel Marcus, Dec 27 2015

CROSSREFS

Sequence in context: A288131 A287499 A287535 * A281757 A280464 A282262

Adjacent sequences:  A004282 A004283 A004284 * A004286 A004287 A004288

KEYWORD

nonn,base

AUTHOR

David W. Wilson

EXTENSIONS

a(33) corrected by Sean A. Irvine, Dec 26 2015

More terms from Michel Marcus, Dec 27 2015

STATUS

approved

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Last modified September 22 05:47 EDT 2019. Contains 327287 sequences. (Running on oeis4.)