A032804 Numbers whose set of base-4 digits is {2,3}.

2, 3, 10, 11, 14, 15, 42, 43, 46, 47, 58, 59, 62, 63, 170, 171, 174, 175, 186, 187, 190, 191, 234, 235, 238, 239, 250, 251, 254, 255, 682, 683, 686, 687, 698, 699, 702, 703, 746, 747, 750, 751, 762, 763, 766, 767, 938, 939, 942

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• easy

Comments

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

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• Index entries for 10-automatic sequences.

Crossrefs

Cf. A007090.

Programs

Maple

A032804:= proc(n) option remember;
   if n::even then 4*procname(n/2-1)+3
   else 4*procname((n-1)/2)+2
   fi
end proc;
A032804(0):=0; # Robert Israel, May 05 2014

Mathematica

Select[Range[1000],Min[IntegerDigits[#,4]]>1&] (* Harvey P. Dale, Dec 23 2013 *)
Table[FromDigits[#,4]&/@Tuples[{2,3},n],{n,5}]//Flatten (* Harvey P. Dale, Jun 09 2024 *)

Formula

a(0) = 0, a(2*n) = 4*a(n-1) + 3, a(2*n+1) = 4*a(n)+2. - Robert Israel, May 05 2014