A044449 Numbers n such that string 1,3 occurs in the base 4 representation of n but not of n+1.

7, 23, 31, 39, 55, 71, 87, 95, 103, 127, 135, 151, 159, 167, 183, 199, 215, 223, 231, 247, 263, 279, 287, 295, 311, 327, 343, 351, 359, 383, 391, 407, 415, 423, 439, 511, 519, 535, 543, 551, 567, 583, 599, 607, 615, 639, 647, 663

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n,4],{1,3}]>0,1,0],{n,700}],{1,0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* Harvey P. Dale, Apr 19 2015 *)