A345387 Numbers k such that k, 2k, 3k, 4k all contain digit 1.

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

Offset: 1

Author

Tanya Khovanova, Jun 17 2021

Keywords

• nonn
• base

Examples

			The first four multiples of 531 are 531, 1062, 1593, and 2124. All of them contain digit 1.
		

Crossrefs

Cf. A011531.

Programs

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 &]

Python

def ok(n): return all('1' in str(k*n) for k in [1, 2, 3, 4])
print(list(filter(ok, range(5155)))) # Michael S. Branicky, Jun 17 2021