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%I #23 May 28 2023 02:01:25
%S 16,48,65,67,68,76,80,112,193,195,196,204,208,240,261,263,269,271,273,
%T 275,276,284,305,307,308,316,321,323,324,332,336,368,449,451,452,460,
%U 464,496,773,775,781,783,785,787,788,796,817
%N Numbers whose base-4 representation contains exactly two 0's and no 2's.
%C If k is in the sequence, then so are 4*k+1 and 4*k+3 but not 4*k or 4*k+2. - _Robert Israel_, Jan 19 2023
%H Robert Israel, <a href="/A045047/b045047.txt">Table of n, a(n) for n = 1..10000</a>
%p filter:= proc(n) local L; L:= convert(n,base,4);
%p not member(2,L) and numboccur(0,L)=2
%p end proc:
%p select(filter, [$1..1000]); # _Robert Israel_, Jan 19 2023
%Y Cf. A007090.
%K nonn,base
%O 1,1
%A _Clark Kimberling_