login
A004288
Least positive multiple of n written in base 8 using only 0 and 1.
2
1, 10, 11, 10, 101, 110, 1111111, 10, 11, 1010, 10111, 110, 101, 11111110, 1111, 100, 10001, 110, 1001, 1010, 101011111, 101110, 101001, 110, 1011111, 1010, 1001, 11111110, 1010011, 11110, 11111, 100, 100001, 100010, 100111111, 110
OFFSET
1,2
MAPLE
f:= proc(n) local R, S, m, p, Snew, s;
R[1]:= 1; R[0]:= 0; S:= {0, 1};
for m from 1 do
p:= 8^m mod n;
Snew:= map(s -> s + p mod n, S);
if member(0, Snew) then return R[-p mod n]+10^m fi;
for s in Snew minus S do R[s] := R[s - p mod n] + 10^m od;
S:= S union Snew;
od
end proc:
1, seq(f(n), n=2..100); # Robert Israel, Dec 30 2014
PROG
(Python)
def A004288(n):
if n > 0:
for i in range(1, 2**n):
s = bin(i)[2:]
if not int(s, 8) % n:
return int(s)
return 0 # Chai Wah Wu, Dec 30 2014
CROSSREFS
Sequence in context: A082492 A004053 A077812 * A065016 A087381 A136400
KEYWORD
nonn,base
EXTENSIONS
a(11), a(22), a(25) corrected by Chai Wah Wu, Dec 30 2014
Initial 0 deleted and offset corrected by N. J. A. Sloane, Jan 31 2024
STATUS
approved