A043941 Numbers k such that 1 and 4 occur juxtaposed in the base-8 representation of k but not of k+1.

12, 33, 76, 103, 140, 161, 204, 225, 271, 289, 332, 353, 396, 417, 460, 481, 524, 545, 588, 615, 652, 673, 716, 737, 831, 844, 865, 908, 929, 972, 993, 1036, 1057, 1100, 1127, 1164, 1185, 1228, 1249, 1295, 1313, 1356, 1377

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A007094.

Programs

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n,8],{1,4}]>0 || SequenceCount[ IntegerDigits[n,8],{4,1}]>0 ,1,0],{n,1500}],{1,0}][[;;,1]] (* Harvey P. Dale, Feb 10 2024 *)