%I #12 Dec 12 2023 08:10:20
%S 3,3,6,9,6,6,3,9,3,3,6,9,6,6,3,9,3,3,6,9,6,6,3,9,3,3,6,9,6,6,3,9
%N Digital root of 3*A000045(n).
%C Period 8.
%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,1)
%F a(n+1) = sum of digits of a(n) + a(n-1).
%F a(n) = A010888(3*A000045(n)). - _R. J. Mathar_, Nov 03 2016
%F G.f.: -3*x*(1+x+2*x^2+3*x^3+2*x^4+2*x^5+x^6+3*x^7) / ( (x-1)*(1+x)*(x^2+1)*(x^4+1) ). - _R. J. Mathar_, Nov 03 2016
%Y Cf. A049341,A000045,A030132,A082115
%K nonn,base,easy
%O 1,1
%A _Mark Dols_, Aug 24 2009