A043942 Numbers k such that 1 and 5 occur juxtaposed in the base-8 representation of k but not of k+1.

13, 41, 77, 111, 141, 169, 205, 233, 269, 297, 335, 361, 397, 425, 461, 489, 525, 553, 589, 623, 653, 681, 717, 745, 781, 809, 895, 909, 937, 973, 1001, 1037, 1065, 1101, 1135, 1165, 1193, 1229, 1257, 1293, 1321, 1359, 1385

Offset

1,1

Links

Table of n, a(n) for n=1..43.

Mathematica

Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 8], {1, 5}]>0||SequenceCount[IntegerDigits[n, 8], {5, 1}]>0, 1, 0], {n, 1500}], {1, 0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* Harvey P. Dale, Jun 09 2016 *)

Crossrefs

Cf. A007094.

Sequence in context: A039339 A031373 A043162 * A004624 A045473 A102083

Adjacent sequences: A043939 A043940 A043941 * A043943 A043944 A043945

Keyword

nonn,base

Author

Clark Kimberling

Status

approved