login
Numbers with exactly 4 2's in their ternary expansion of n.
4

%I #15 Oct 10 2024 15:12:25

%S 80,161,188,215,224,233,236,239,240,241,323,404,431,458,467,476,479,

%T 482,483,484,512,539,548,557,560,563,564,565,593,620,629,638,641,644,

%U 645,646,656,665,668,671,672,673,683,692,695

%N Numbers with exactly 4 2's in their ternary expansion of n.

%H Seiichi Manyama, <a href="/A023702/b023702.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[ Range[ 729 ], (Count[ IntegerDigits[ #, 3 ], 2 ]==4)& ]

%t Select[Range[700],DigitCount[#,3,2]==4&] (* _Harvey P. Dale_, Oct 10 2024 *)

%K nonn,base,easy

%O 1,1

%A _Olivier GĂ©rard_