%I #12 May 21 2023 12:25:07

%S 22015,22399,22495,22519,22525,23935,24031,24055,24061,24415,24439,

%T 24445,24535,24541,24565,30079,30175,30199,30205,30559,30583,30589,

%U 30679,30685,30709,32095,32119,32125,32215,32221

%N Numbers whose base-4 representation contains exactly four 1's and four 3's.

%Y Cf. A007090.

%K nonn,base

%O 1,1

%A _Clark Kimberling_