A140467 Numbers k such that the digits of k are not present in 3k.

1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 16, 18, 19, 21, 22, 23, 26, 27, 29, 32, 33, 34, 36, 37, 38, 39, 43, 44, 46, 54, 58, 59, 63, 64, 66, 67, 68, 69, 73, 74, 76, 77, 78, 81, 83, 84, 87, 88, 89, 91, 94, 96, 108, 109, 111, 112, 116, 118, 119, 121, 122, 126, 129, 136, 158, 159, 161

Offset: 1

Author

Jonathan Vos Post, Jun 25 2008

Keywords

• nonn
• base
• easy
• changed

Examples

			169 is in the sequence because the sets {1,6,9} and {5,0,7} are disjoint.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of A129846.

Programs

Maple

a:=proc(n) local nd, n3d: nd:=convert(convert(n,base,10),set): n3d:=convert(convert(3*n,base,10),set): if `intersect`(nd, n3d)={} then n else end if end proc: seq(a(n),n=1..170); # Emeric Deutsch, Jul 20 2008

Mathematica

Select[Range[200],Intersection[IntegerDigits[#],IntegerDigits[3*#]]=={}&] (* Harvey P. Dale, Aug 13 2018 *)

Extensions

More terms from Emeric Deutsch, Jul 20 2008