A044409 Numbers n such that string 7,7 occurs in the base 10 representation of n but not of n-1.

77, 177, 277, 377, 477, 577, 677, 770, 877, 977, 1077, 1177, 1277, 1377, 1477, 1577, 1677, 1770, 1877, 1977, 2077, 2177, 2277, 2377, 2477, 2577, 2677, 2770, 2877, 2977, 3077, 3177, 3277, 3377, 3477, 3577, 3677, 3770, 3877

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {7, 7}]>0, 1, 0], {n, 4000}], {0, 1}][[;; , 2]] (* Harvey P. Dale, Feb 17 2024 *)

Crossrefs

Sequence in context: A046513 A199994 A043518 * A044790 A255095 A391916

Adjacent sequences: A044406 A044407 A044408 * A044410 A044411 A044412

Keyword

nonn,base

Author

Clark Kimberling

Status

approved