A032944 - OEIS

%I #14 Feb 12 2021 22:04:13

%S 1,2,3,4,5,6,7,8,9,18,27,36,45,54,63,72,81,82,83,84,85,86,87,88,89,

%T 162,163,164,165,166,167,168,169,170,243,244,245,246,247,248,249,250,

%U 251,324,325,326,327,328,329,330,331,332,405,406

%N Numbers whose base-9 representation Sum_{i=0..m} d(i)*9^(m-i) has d(i)=0 for all odd i.

%H Robert Israel, <a href="/A032944/b032944.txt">Table of n, a(n) for n = 1..10000</a>

%p b:= 9:

%p f:= proc(n, j) local L, m;

%p   L:= convert(n, base, b);

%p   m:= nops(L);

%p   j*add(L[i+1]*b^(2*i), i=0..m-1)

%p end proc:

%p seq(seq(seq(f(n, j), n=b^k..b^(k+1)-1), j=[1, b]), k=0..2); # _Robert Israel_, Nov 16 2020

%Y Cf. A007095 (numbers in base 9).

%K nonn,base

%O 1,2

%A _Clark Kimberling_

%E Definition corrected by _Robert Israel_, Nov 16 2020