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Numbers whose set of base-4 digits is {2,3}.
4

%I #28 Jun 09 2024 11:46:44

%S 2,3,10,11,14,15,42,43,46,47,58,59,62,63,170,171,174,175,186,187,190,

%T 191,234,235,238,239,250,251,254,255,682,683,686,687,698,699,702,703,

%U 746,747,750,751,762,763,766,767,938,939,942

%N Numbers whose set of base-4 digits is {2,3}.

%C Or, no base-2 digit of a(n) is a base-4 digit of a(n).

%H Robert Israel, <a href="/A032804/b032804.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>.

%F a(0) = 0, a(2*n) = 4*a(n-1) + 3, a(2*n+1) = 4*a(n)+2. - _Robert Israel_, May 05 2014

%p A032804:= proc(n) option remember;

%p if n::even then 4*procname(n/2-1)+3

%p else 4*procname((n-1)/2)+2

%p fi

%p end proc;

%p A032804(0):=0; # _Robert Israel_, May 05 2014

%t Select[Range[1000],Min[IntegerDigits[#,4]]>1&] (* _Harvey P. Dale_, Dec 23 2013 *)

%t Table[FromDigits[#,4]&/@Tuples[{2,3},n],{n,5}]//Flatten (* _Harvey P. Dale_, Jun 09 2024 *)

%Y Cf. A007090.

%K nonn,base,easy

%O 1,1

%A _Clark Kimberling_