cp's OEIS Frontend

A028904 Map n = Sum c_i 10^i to a(n) = Sum c_i 9^i.

%I A028904 #9 Jul 08 2025 18:55:20
%S A028904 0,1,2,3,4,5,6,7,8,9,9,10,11,12,13,14,15,16,17,18,18,19,20,21,22,23,
%T A028904 24,25,26,27,27,28,29,30,31,32,33,34,35,36,36,37,38,39,40,41,42,43,44,
%U A028904 45,45,46,47,48,49,50,51,52,53,54,54,55,56,57,58,59,60,61,62,63,63,64,65,66,67,68,69,70,71,72,72,73,74,75,76,77,78,79,80,81,81,82,83,84,85,86,87,88,89,90,81,82,83,84,85,86,87,88,89,90,90,91,92,93
%N A028904 Map n = Sum c_i 10^i to a(n) = Sum c_i 9^i.
%C A028904 More than the usual number of terms are displayed in order to distinguish this from some closely related sequences. - _N. J. A. Sloane_, Mar 22 2014
%p A028904 f2:=proc(n) local t1,i,L;
%p A028904 t1:=convert(n,base,10);
%p A028904 L:=nops(t1);
%p A028904 add(t1[i]*9^(i-1),i=1..L);
%p A028904 end;
%p A028904 [seq(f2(n),n=0..200)];
%K A028904 nonn,base
%O A028904 0,3
%A A028904 _N. J. A. Sloane_
%E A028904 More terms from _Erich Friedman_.