%I #17 Aug 11 2024 14:41:31

%S 192,219,273,327

%N Numbers k that together with their double and triple contain every digit from 1-9 exactly once.

%D D. Wells, Curious and interesting numbers, Penguin Books, p. 128.

%H P. De Geest, <a href="https://www.worldofnumbers.com/ninedigits.htm">Nine digits digressions</a>

%e k=327 -> 2k=654 -> 3k=981 and 327654981 is a 'nine-digit' number.

%t pdnQ[n_]:=Sort[Flatten[IntegerDigits[{n,2n,3n}]]]==Range[9]; Select[Range[987],pdnQ] (* _Harvey P. Dale_, Jul 07 2012 *)

%Y Cf. A050289.

%K nonn,base,fini,full

%O 0,1

%A _Felice Russo_

%E Corrected by _Patrick De Geest_, Mar 15 2000

%E Better definition from _Tanya Khovanova_, Mar 08 2021