A081609 - OEIS

%I #10 Jun 25 2022 10:01:48

%S 0,1,1,2,3,4,4,5,5,6,7,8,9,10,11,12,13,14,14,15,15,16,17,18,18,19,19,

%T 20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,

%U 43,44,45,46,46,47,47,48,49,50,50,51,51,52,53,54,55,56,57,58,59,60,60,61

%N Number of numbers <= n having at least one 1 in their ternary representation.

%C a(n) + A061392(n) = n+1.

%o (PARI) has(n)=!!setsearch(Set(digits(n,3)),1)

%o first(n)=my(s); vector(n,k,s+=has(k)) \\ _Charles R Greathouse IV_, Sep 02 2015

%Y Cf. A007089, A062756, A081607, A081610, A061392.

%Y Partial sums of A316829.

%K nonn

%O 0,4

%A _Reinhard Zumkeller_, Mar 23 2003