A043825 - OEIS

%I #7 Sep 08 2023 17:18:12

%S 17,18,19,24,25,27,28,29,30,33,34,35,36,38,39,44,45,46,49,50,51,52,54,

%T 55,56,57,59,65,66,67,69,74,79,81,82,83,88,89,91,92,93,94,96,101,104,

%U 105,107,111,112,117,122,124,125,126,129,130

%N Numbers n such that number of runs in the base 4 representation of n is congruent to 0 mod 3.

%t Select[Range[150],Mod[Length[Split[IntegerDigits[#,4]]],3]==0&] (* _Harvey P. Dale_, Sep 08 2023 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_