|
|
A345387
|
|
Numbers k such that k, 2k, 3k, 4k all contain digit 1.
|
|
0
|
|
|
531, 541, 1053, 1054, 2571, 3051, 3061, 3071, 3105, 3106, 3107, 3157, 3551, 3561, 3571, 3581, 3591, 4051, 4061, 4071, 4081, 4091, 4105, 4106, 4107, 4108, 4109, 4155, 4156, 4157, 4158, 4159, 4551, 4561, 4571, 4581, 4591, 5031, 5041, 5103, 5104, 5128, 5129, 5153, 5154
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
The first four multiples of 531 are 531, 1062, 1593, and 2124. All of them contain digit 1.
|
|
MATHEMATICA
|
Select[Range[10000], Length[ Position[IntegerDigits[#], 1]] > 0 && Length[ Position[IntegerDigits[2 #], 1]] > 0 && Length[ Position[IntegerDigits[3 #], 1]] > 0 && Length[ Position[IntegerDigits[4 #], 1]] > 0 &]
|
|
PROG
|
(Python)
def ok(n): return all('1' in str(k*n) for k in [1, 2, 3, 4])
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|