A004285 Least positive multiple of n written in base 5 using only 0 and 1.

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

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