%I A014575
%S A014575 1260,1395,1435,1530,1827,2187,6880,102510,104260,105210,105264,
%T A014575 105750,108135,110758,115672,116725,117067,118440,120600,123354,
%U A014575 124483,125248,125433,125460,125500,126027,126846,129640
%N A014575 Vampire numbers (definition 2): numbers n with an even number of digits
which have a factorization n = i*j where length(i) = length(j) =
length(n)/2 and the multiset of the digits of n coincides with the
multiset of the digits of i and j.
%C A014575 The numbers i and j may not both have trailing zeros. Numbers may have
more than one such factorization. However, each n is listed only
once. [Comment modified by Rick L. Shepherd (rshepherd2(AT)hotmail.com),
Nov 02 2009]
%D A014575 C. A. Pickover, "Vampire Numbers." Ch. 30 in Keys to Infinity. New York:
Wiley, pp. 227-231, 1995.
%H A014575 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
VampireNumber.html">Link to a section of The World of Mathematics.</
a>
%e A014575 1260 = 21*60, 1395 = 15*93, 1435 = 35*41, 1530 = 30*51, etc.
%Y A014575 The following sequences are all closely related: A020342, A014575, A080718,
A048936, A144563.
%Y A014575 Cf. A048933, A048934, ..., A048939.
%Y A014575 Sequence in context: A159726 A048130 A099592 this_sequence A144563 A158737
A047634
%Y A014575 Adjacent sequences: A014572 A014573 A014574 this_sequence A014576 A014577
A014578
%K A014575 nonn,base,new
%O A014575 1,1
%A A014575 Eric Weisstein (eric(AT)weisstein.com)
%E A014575 Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 03 2009
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