The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #11 Mar 16 2020 18:24:27
%S 0,1,2,3,4,5,6,7,8,9,9,10,11,12,13,14,15,16,17,18,17,18,19,20,21,22,
%T 23,24,25,26,24,25,26,27,28,29,30,31,32,33,30,31,32,33,34,35,36,37,38,
%U 39,35,36,37,38,39,40,41,42,43,44,39,40,41,42,43,44,45,46
%N Sum of digits of n written in fractional base 10/9.
%C The base 10/9 expansion is unique and thus the sum of digits function is well-defined.
%F a(n) = A007953(A024664(n)).
%e In base 10/9 the number 14 is represented by 94 and so a(14) = 9 + 4 = 13.
%o (Sage) # uses [basepqsum from A245355]
%o [basepqsum(10,9,w) for w in [0..200]]
%Y Cf. A024664, A007953, A000120, A244040.
%K nonn,base
%O 0,3
%A _Hailey R. Olafson_, Jul 18 2014