A094128 - OEIS

%I #11 Jun 14 2014 12:57:01

%S 44,116,128,132,152,296,320,332,344,348,380,384,396,440,452,456,464,

%T 476,800,872,880,888,944,960,980,992,996,1024,1028,1032,1044,1136,

%U 1140,1152,1184,1188,1196,1232,1280,1304,1316,1320,1352,1356,1368

%N Numbers n that can be factorized n=x*y and containing in their ternary representation the same digits the same number of times as x and y together.

%H J. K. Andersen, <a href="http://primerecords.dk/vampires">Vampire Numbers</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/VampireNumber.html">Vampire Number</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Ternary.html">Ternary</a>

%e 320=16*20, 320->'102212' with 1x'0', 2x'1' and 3x'2': 16->'121' and 20->'202' have together the same ternary digits the same number of times, therefore 320 is a term.

%Y Cf. A020342, A048936, A007089.

%K nonn,base

%O 1,1

%A _Reinhard Zumkeller_, Jun 01 2004