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A023694
Numbers with exactly 3 1's in ternary expansion.
4
13, 31, 37, 39, 41, 43, 49, 67, 85, 91, 93, 95, 97, 103, 109, 111, 113, 115, 117, 119, 123, 125, 127, 129, 131, 133, 139, 145, 147, 149, 151, 157, 175, 193, 199, 201, 203, 205, 211, 229, 247, 253, 255, 257, 259, 265, 271, 273, 275, 277, 279, 281, 285, 287, 289
OFFSET
1,1
LINKS
MAPLE
q:= n-> numboccur(1, convert(n, base, 3))=3:
select(q, [$1..300])[]; # Alois P. Heinz, Mar 15 2020
MATHEMATICA
Select[ Range[ 270 ], (Count[ IntegerDigits[ #, 3 ], 1 ]==3)& ]
CROSSREFS
Sequence in context: A156532 A227435 A046414 * A038465 A103665 A040050
KEYWORD
nonn,base,easy
STATUS
approved