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%I #11 May 06 2024 12:38:06
%S 1,1,2,4,8,16,23,28,29,31,35,43,50,55,56,58,62,70,77,82,83,85,89,97,
%T 104,109,110,112,116,124,131,136,137,139,143,151,158,163,164,166,170,
%U 178,185,190,191,193,197,205
%N a(n) is the sum of the digital roots of all of the previous terms.
%C Essentially identical to A007612, which is the main entry for this sequence. - _N. J. A. Sloane_, Aug 25 2007
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,-1,2,-1).
%F G.f.: x*(5*x^5+x^4+2*x^3+x^2-x+1) / ((x-1)^2*(x+1)*(x^2-x+1)). - _Colin Barker_, Jan 17 2014
%e a(8) = 28 because the digital roots of the previous terms are 1,1,2,4,8,7 and 5 and 1+1+2+4+8+7+5 = 28
%o (PARI) Vec(x*(5*x^5+x^4+2*x^3+x^2-x+1)/((x-1)^2*(x+1)*(x^2-x+1)) + O(x^100)) \\ _Colin Barker_, Jan 17 2014
%Y Cf. A007612.
%K easy,nonn,base
%O 1,3
%A Stephen Casey (hexomino(AT)gmail.com), Aug 23 2007