A044059 Numbers n such that string 2,1 occurs in the base 3 representation of n but not of n-1.

7, 16, 21, 25, 34, 43, 48, 52, 61, 63, 75, 79, 88, 97, 102, 106, 115, 124, 129, 133, 142, 144, 156, 160, 169, 178, 183, 187, 189, 223, 225, 237, 241, 250, 259, 264, 268, 277, 286, 291, 295, 304, 306, 318, 322, 331, 340, 345, 349

Offset

1,1

Links

Table of n, a(n) for n=1..49.

Mathematica

Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 3], {2, 1}]>0, 1, 0], {n, 400}], {0, 1}]][[2]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* Harvey P. Dale, Feb 08 2016 *)

Crossrefs

Sequence in context: A060914 A242917 A370921 * A287369 A342743 A368407

Adjacent sequences: A044056 A044057 A044058 * A044060 A044061 A044062

Keyword

nonn,base

Author

Clark Kimberling

Status

approved