%I
%S 2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,
%T 5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,
%U 5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4,2,4,5,7,5,4
%N Digital root of A003500(n).
%C Periodic with cycle of length 6: {2,4,5,7,5,4}. a(n) may be expressed as the decimal expansion of 246/1001. Sequence is palindromic.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 1, 1).
%F a(n) = 4*a(n1)  a(n2), reduced to digital root.
%F a(n) = digital root of (2 + sqrt(3))^n + ( 2  sqrt(3))^n.
%t LinearRecurrence[{1, 0, 1, 1}, {2, 4, 5, 7}, 102] (* _Ray Chandler_, Jul 25 2016*)
%Y Cf. A010888, A003500.
%K nonn,base
%O 0,1
%A _Peter M. Chema_, Dec 17 2014
%E More terms from _Ray Chandler_, Jul 25 2016
