A044030 Numbers k such that 4 and 9 occur juxtaposed in the base-10 representation of k but not of k+1.

49, 94, 149, 194, 249, 294, 349, 394, 449, 499, 549, 594, 649, 694, 749, 794, 849, 894, 949, 994, 1049, 1094, 1149, 1194, 1249, 1294, 1349, 1394, 1449, 1499, 1549, 1594, 1649, 1694, 1749, 1794, 1849, 1894, 1949, 1994, 2049

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {4, 9}]>0 || SequenceCount[IntegerDigits[n], {9, 4}]>0, 1, 0], {n, 2100}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 20 2019 *)

Crossrefs

Sequence in context: A031180 A039427 A043250 * A165339 A131601 A309541

Adjacent sequences: A044027 A044028 A044029 * A044031 A044032 A044033

Keyword

nonn,base

Author

Clark Kimberling

Status

approved