A043162 Numbers k such that 1 and 5 occur juxtaposed in the base-8 representation of k but not of k-1.

13, 41, 77, 104, 141, 169, 205, 233, 269, 297, 328, 361, 397, 425, 461, 489, 525, 553, 589, 616, 653, 681, 717, 745, 781, 809, 832, 909, 937, 973, 1001, 1037, 1065, 1101, 1128, 1165, 1193, 1229, 1257, 1293, 1321, 1352, 1385

Offset

1,1

Links

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

Mathematica

j15Q[n_]:=Module[{idn8=IntegerDigits[n, 8]}, SequenceCount[idn8, {1, 5}]>0 || SequenceCount[idn8, {5, 1}]>0]; Transpose[ SequencePosition[Table[If[ j15Q[k], 1, 0], {k, 1500}], {0, 1}]][[2]] (* The program uses the SequenceCount and SequencePosition functions from Mathematica version 10 *) (* Harvey P. Dale, Aug 09 2015 *)

Crossrefs

Cf. A007094.

Sequence in context: A146238 A039339 A031373 * A043942 A004624 A045473

Adjacent sequences: A043159 A043160 A043161 * A043163 A043164 A043165

Keyword

nonn,base

Author

Clark Kimberling

Status

approved