A044040 - OEIS

A044040

Numbers k such that 8 and 9 occur juxtaposed in the base-10 representation of k but not of k+1.

89, 98, 189, 198, 289, 298, 389, 398, 489, 498, 589, 598, 689, 698, 789, 798, 899, 989, 998, 1089, 1098, 1189, 1198, 1289, 1298, 1389, 1398, 1489, 1498, 1589, 1598, 1689, 1698, 1789, 1798, 1899, 1989, 1998, 2089, 2098, 2189

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..41.

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {8, 9}]>0 || SequenceCount[IntegerDigits[n], {9, 8}]>0, 1, 0], {n, 2200}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 24 2018 *)

CROSSREFS

Sequence in context: A240510 A039437 A043260 * A065318 A226241 A033254

Adjacent sequences: A044037 A044038 A044039 * A044041 A044042 A044043

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved