|
| |
|
|
A199988
|
|
Numbers whose product of digits is 6.
|
|
3
|
|
|
|
6, 16, 23, 32, 61, 116, 123, 132, 161, 213, 231, 312, 321, 611, 1116, 1123, 1132, 1161, 1213, 1231, 1312, 1321, 1611, 2113, 2131, 2311, 3112, 3121, 3211, 6111, 11116, 11123, 11132, 11161, 11213, 11231, 11312, 11321, 11611, 12113, 12131, 12311, 13112, 13121
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
|
|
|
MAPLE
|
f:= proc(d) local b, i, t;
b:= (10^d-1)/9;
op(sort([seq(b+5*10^i, i=0..d-1), seq(b+10^t[1]+2*10^t[2], t = combinat:-permute([$0..d-1], 2))]))
end proc:
|
|
|
MATHEMATICA
|
Select[Range[20000], Times @@ IntegerDigits[#] == 6 &] (* T. D. Noe, Nov 16 2011 *)
|
|
|
PROG
|
(Python)
from sympy import prod
from sympy.utilities.iterables import multiset_permutations
def agen(maxdigits):
for digs in range(1, maxdigits+1):
for mp in multiset_permutations("1"*(digs-1) + "236", digs):
if prod(map(int, mp)) == 6: yield int("".join(mp))
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
