A044968 Numbers whose base-3 representation contains no 0's and exactly three 1's.

13, 41, 43, 49, 67, 125, 131, 133, 149, 151, 157, 203, 205, 211, 229, 377, 395, 401, 403, 449, 455, 457, 473, 475, 481, 611, 617, 619, 635, 637, 643, 689, 691, 697, 715, 1133, 1187, 1205, 1211, 1213, 1349, 1367, 1373, 1375, 1421, 1427, 1429, 1445, 1447, 1453

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

sort([seq(seq(3^d-1-add(3^j, j=s), s=combinat:-choose([$0..(d-1)], 3)), d=3..8)]); # Robert Israel, Mar 29 2023

Mathematica

Select[Range[1500], DigitCount[#, 3, 0]==0&&DigitCount[#, 3, 1]==3&] (* Harvey P. Dale, Feb 27 2023 *)

Crossrefs

Cf. A007089.

Sequence in context: A041755 A229768 A251100 * A108226 A337146 A122730

Adjacent sequences: A044965 A044966 A044967 * A044969 A044970 A044971

Keyword

nonn,base

Author

Clark Kimberling

Status

approved