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Numbers whose base-4 representation contains no 1's and exactly four 2's.
0

%I #11 May 21 2023 12:28:40

%S 170,554,650,674,680,683,686,698,746,938,2090,2186,2210,2216,2219,

%T 2222,2234,2282,2570,2594,2600,2603,2606,2618,2690,2696,2699,2702,

%U 2720,2723,2732,2735,2738,2744,2747,2750,2762,2786

%N Numbers whose base-4 representation contains no 1's and exactly four 2's.

%t Select[Range[3000],DigitCount[#,4,1]==0&&DigitCount[#,4,2]==4&] (* _Harvey P. Dale_, May 09 2015 *)

%Y Cf. A007090.

%K nonn,base

%O 1,1

%A _Clark Kimberling_