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

1,2

Links

Table of n, a(n) for n=1..67.

Example

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

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 *)

Crossrefs

Sequence in context: A004436 A028237 A194463 * A103677 A087919 A113508

Adjacent sequences: A140464 A140465 A140466 * A140468 A140469 A140470

Keyword

nonn,base,easy

Author

Jonathan Vos Post, Jun 25 2008

Extensions

More terms from Emeric Deutsch, Jul 20 2008

Status

approved