A043858 - OEIS

%I #7 Oct 01 2018 20:16:30

%S 69905,69906,69907,69912,69913,69915,69916,69917,69918,69921,69922,

%T 69923,69924,69926,69927,69932,69933,69934,69937,69938,69939,69940,

%U 69942,69943,69944,69945,69947,70020,70022,70023

%N Numbers n such that number of runs in the base 4 representation of n is congruent to 0 mod 9.

%t Select[Range[80000],Mod[Length[Split[IntegerDigits[#,4]]],9]==0&] (* _Harvey P. Dale_, Oct 01 2018 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_