A043228 Numbers k such that 1 and 5 occur juxtaposed in the base-10 representation of k but not of k-1.

15, 51, 115, 150, 215, 251, 315, 351, 415, 451, 510, 551, 615, 651, 715, 751, 815, 851, 915, 951, 1015, 1051, 1115, 1150, 1215, 1251, 1315, 1351, 1415, 1451, 1500, 1615, 1651, 1715, 1751, 1815, 1851, 1915, 1951, 2015, 2051

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {1, 5}]>0 || SequenceCount[ IntegerDigits[n], {5, 1}]>0, 1, 0], {n, 2100}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 15 2020 *)

Crossrefs

Sequence in context: A098831 A265039 A039405 * A044008 A201054 A009962

Adjacent sequences: A043225 A043226 A043227 * A043229 A043230 A043231

Keyword

nonn,base

Author

Clark Kimberling

Status

approved