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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
OFFSET
1,2
LINKS
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
KEYWORD
nonn,base
EXTENSIONS
a(33) corrected by Sean A. Irvine, Dec 26 2015
More terms from Michel Marcus, Dec 27 2015
STATUS
approved