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A044012

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

19, 91, 119, 199, 219, 291, 319, 391, 419, 491, 519, 591, 619, 691, 719, 791, 819, 891, 919, 991, 1019, 1091, 1119, 1199, 1219, 1291, 1319, 1391, 1419, 1491, 1519, 1591, 1619, 1691, 1719, 1791, 1819, 1891, 1999, 2019, 2091

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OFFSET

1,1

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {1, 9}]>0 || SequenceCount[ IntegerDigits[n], {9, 1}]>0, 1, 0], {n, 2100}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 12 2019 *)

CROSSREFS

Sequence in context: A039409 A038653 A043232 * A288485 A214532 A118294

Adjacent sequences: A044009 A044010 A044011 * A044013 A044014 A044015

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

URL: https://oeis.org/A044012

⇱ A044012 - OEIS