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%I #4 Mar 30 2012 17:39:14
%S 123,6,12,15,21,24,30,33,39,51,57,69,84,96,111,114,120,123,129,141,
%T 147,159,174,186,201,204,210,213,219,231,237,249,264,276,291,303,309,
%U 321,327,339,354,366,381,393,408,420,426,438,453,465,480,492,507,519,534
%N a(1) = 123, a(n) = sum of digits of all previous terms.
%C a(1) = 123 a(2) = 1 + 2 + 3 = 6 a(3) = (1 + 2 + 3) + 6 = 12 a(4) = (1 + 2 + 3) + 6 + (1 + 2) = 15 a(5) = (1 + 2 + 3) + 6 + (1 + 2) + (1 + 5) = 21 a(6) = (1 + 2 + 3) + 6 + (1 + 2) + (1 + 5) + (2 + 1) = 24 a(7) = (1 + 2 + 3) + 6 + (1 + 2) + (1 + 5) + (2 + 1) + (2 + 4) = 30 ...
%C Essentially the same as A016052. - _R. J. Mathar_, Jun 18 2008
%H Sergio Silva, <a href="http://ginasiomental.no.sapo.pt/materialc/mteste/teste.htm">Teste Numerico</a>.
%F a(n) = a(n-1) + sum of digits of a(n-1), a(1) = 123
%o (PARI) s=0; a=123; print1(a,","); for(n=1,100,dig=eval(Vec(Str(a)));s=s+sum(i=1,length(dig),dig[i]);print1(s,",");a=s)
%Y Cf. A004207.
%K nonn,base
%O 1,1
%A Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 02 2006
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