A044240 Numbers k such that string 6,5 occurs in the base 8 representation of k but not of k-1.

53, 117, 181, 245, 309, 373, 424, 437, 501, 565, 629, 693, 757, 821, 885, 936, 949, 1013, 1077, 1141, 1205, 1269, 1333, 1397, 1448, 1461, 1525, 1589, 1653, 1717, 1781, 1845, 1909, 1960, 1973, 2037, 2101, 2165, 2229, 2293, 2357

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• changed

Links

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

Crossrefs

Cf. A007094.

Programs

Mathematica

A044240Q[k_] := StringContainsQ[IntegerString[k, 8], "65"] && StringFreeQ[IntegerString[k - 1, 8], "65"];
Select[Range[5000], A044240Q] (* Paolo Xausa, Sep 03 2025 *)