%I #8 Jun 13 2015 00:49:17
%S 1,4,18,75,301,1204,4818,19275,77101,308404,1233618,4934475,19737901,
%T 78951604,315806418,1263225675,5052902701,20211610804,80846443218,
%U 323385772875,1293543091501,5174172366004,20696689464018,82786757856075
%N Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,2,3.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-5,5,-4).
%F G.f.: x*(1-x+3*x^2) / ( (x-1)*(4*x-1)*(x^2+1) ). - _R. J. Mathar_, May 04 2015
%K nonn,base,easy
%O 1,2
%A _Clark Kimberling_