A031466 - OEIS

%I #14 Jul 04 2021 14:11:29

%S 3,7,11,13,14,23,27,29,30,39,43,45,46,51,53,54,57,58,60,79,87,91,93,

%T 94,103,107,109,110,115,117,118,121,122,124,143,151,155,157,158,167,

%U 171,173,174,179,181,182,185,186,188,199,203,205

%N Numbers whose base-4 representation has one fewer 0 than 3's.

%C Numbers n such that A160383(n) - A160380(n) = 1. - _Robert Israel_, Jun 05 2018

%H Robert Israel, <a href="/A031466/b031466.txt">Table of n, a(n) for n = 1..10000</a>

%p filter:= proc(n) local L;

%p   L:= convert(n,base,4);

%p   numboccur(3,L) - numboccur(0,L)=1

%p end proc:

%p select(filter, [$1..300]); # _Robert Israel_, Jun 05 2018

%t Select[Range[210],DigitCount[#,4,0]==DigitCount[#,4,3]-1&] (* _Harvey P. Dale_, Dec 16 2011 *)

%Y Cf. A007090, A160380, A160383.

%K nonn,base

%O 1,1

%A _Clark Kimberling_