A044271 - OEIS

A044271

Numbers n such that string 2,2 occurs in the base 9 representation of n but not of n-1.

20, 101, 180, 263, 344, 425, 506, 587, 668, 749, 830, 909, 992, 1073, 1154, 1235, 1316, 1397, 1478, 1559, 1620, 1721, 1802, 1883, 1964, 2045, 2126, 2207, 2288, 2367, 2450, 2531, 2612, 2693, 2774, 2855, 2936, 3017, 3096

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..39.

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {2, 2}]>0, 1, 0], {n, 4000}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 29 2018 *)

CROSSREFS

Sequence in context: A239857 A041772 A043462 * A044652 A041774 A043217

Adjacent sequences: A044268 A044269 A044270 * A044272 A044273 A044274

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved