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A043188
Numbers k such that 1 and 2 occur juxtaposed in the base-9 representation of k but not of k-1.
0
11, 19, 92, 99, 171, 181, 254, 262, 335, 343, 416, 424, 497, 505, 578, 586, 659, 667, 740, 748, 821, 828, 891, 983, 991, 1064, 1072, 1145, 1153, 1226, 1234, 1307, 1315, 1388, 1396, 1469, 1477, 1539, 1629, 1639, 1712, 1720
OFFSET
1,1
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {1, 2}]>0 || SequenceCount[ IntegerDigits[n, 9], {2, 1}]>0, 1, 0], {n, 2000}], {0, 1}][[All, 2]] (* Harvey P. Dale, Nov 24 2022 *)
CROSSREFS
Cf. A007095.
Sequence in context: A039365 A103201 A199338 * A043968 A199329 A121132
KEYWORD
nonn,base
STATUS
approved