%I A162219
%S A162219 0,1,2,3,8,9,28,29,32,33,35,43,55,62,83,128,129,243,512,513,922,2048,
%T A162219 2049,2316,2317,2444,2445,2571,2699,7330,8192,8193,13124,13125,20710,
%U A162219 21222,32768,32769,40392,40393,131072,131073,524288,524289,1075174
%N A162219 Base 4 perfect digital invariants (written in base 10): numbers equal 
               to the sum of the kth powers of their base-4 digits, for some k.
%H A162219 Joseph Myers, <a href="b162219.txt">Table of n, a(n) for n=1..6778</a> 
               (complete to 1500 base 4 digits)
%Y A162219 Cf. A162220 (corresponding exponents), A010344 (restriction to power 
               = number of digits), A033836, A162221. In other bases: A162216 (base 
               3), A162222 (base 5), A162225 (base 6), A162228 (base 7), A162231 
               (base 8), A162234 (base 9), A023052 (base 10).
%Y A162219 Sequence in context: A085453 A030439 A119386 this_sequence A140484 A087034 
               A133165
%Y A162219 Adjacent sequences: A162216 A162217 A162218 this_sequence A162220 A162221 
               A162222
%K A162219 base,nonn
%O A162219 1,3
%A A162219 Joseph Myers (jsm(AT)polyomino.org.uk), Jun 28 2009