A044123 Numbers n such that string 3,3 occurs in the base 6 representation of n but not of n-1.

21, 57, 93, 126, 165, 201, 237, 273, 309, 342, 381, 417, 453, 489, 525, 558, 597, 633, 669, 705, 741, 756, 813, 849, 885, 921, 957, 990, 1029, 1065, 1101, 1137, 1173, 1206, 1245, 1281, 1317, 1353, 1389, 1422, 1461, 1497, 1533, 1569, 1605, 1638, 1677, 1713

Offset

1,1

Links

Table of n, a(n) for n=1..48.

Mathematica

f[n_] := Length[StringPosition[ToString[FromDigits[IntegerDigits[n, 6]]], "33", 1]]; Select[Table[n, {n, 10000}], f[#] > 0 && f[# - 1] == 0 &] (* Vladimir Joseph Stephan Orlovsky, Jul 20 2011 *)
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 6], {3, 3}]>0, 1, 0], {n, 2000}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 14 2017 *)

Crossrefs

Cf. A044504.

Sequence in context: A174969 A176069 A043382 * A044504 A118057 A327902

Adjacent sequences: A044120 A044121 A044122 * A044124 A044125 A044126

Keyword

nonn,base

Author

Clark Kimberling

Status

approved