A044339 Numbers k such that the string 0,7 occurs in the base 10 representation of k but not of k-1.

107, 207, 307, 407, 507, 607, 707, 807, 907, 1007, 1070, 1107, 1207, 1307, 1407, 1507, 1607, 1707, 1807, 1907, 2007, 2070, 2107, 2207, 2307, 2407, 2507, 2607, 2707, 2807, 2907, 3007, 3070, 3107, 3207, 3307, 3407, 3507, 3607, 3707, 3807, 3907, 4007, 4070, 4107, 4207, 4307

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Mathematica

A044339Q[k_] := StringContainsQ[IntegerString[k], "07"] && StringFreeQ[IntegerString[k - 1], "07"];
Select[Range[5000], A044339Q] (* Paolo Xausa, Nov 03 2025 *)

Crossrefs

Sequence in context: A387306 A250147 A142270 * A044720 A134297 A141996

Adjacent sequences: A044336 A044337 A044338 * A044340 A044341 A044342

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Nov 03 2025

Status

approved