%I A125122
%S A125122 0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,1,0,1,
%T A125122 0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,
%U A125122 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0
%N A125122 First differences of A034888.
%C A125122 This sequence is not periodic because log(3)/log(10) is an irrational 
               number. - T. D. Noe (noe(AT)sspectra.com), Jan 10 2007
%F A125122 a(n)=Number_of_digits{3^(n+1)}-Number_of digits{3^(n)} with n>=0.
%e A125122 a(1)=0 because 3^(1+1)=9 (one digit) 3^1=3 (one digit) and the difference 
               is 0
%e A125122 a(4)=1 because 3^(4+1)=243 (three digits) 3^(4)=81 (two digits) and the 
               difference is 1
%p A125122 P:=proc(n) local i,j,k,w,old; k:=3; for i from 1 by 1 to n do j:=k^i; 
               w:=0; while j>0 do w:=w+1; j:=trunc(j/10); od; if i>1 then print(w-old); 
               old:=w; else old:=w; fi; od; end: P(1000);
%Y A125122 Sequence in context: A141743 A112416 A061265 this_sequence A000035 A131734 
               A134452
%Y A125122 Adjacent sequences: A125119 A125120 A125121 this_sequence A125123 A125124 
               A125125
%K A125122 easy,nonn,base
%O A125122 0,1
%A A125122 Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jan 10 2007