A044073 - OEIS

A044073

Numbers k such that string 3,0 occurs in the base 4 representation of k but not of k-1.

12, 28, 44, 48, 60, 76, 92, 108, 112, 124, 140, 156, 172, 176, 188, 192, 220, 236, 240, 252, 268, 284, 300, 304, 316, 332, 348, 364, 368, 380, 396, 412, 428, 432, 444, 448, 476, 492, 496, 508, 524, 540, 556, 560, 572, 588, 604, 620, 624, 636, 652, 668, 684, 688, 700

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

MATHEMATICA

A044073Q[k_] := StringContainsQ[IntegerString[k, 4], "30"] && StringFreeQ[IntegerString[k - 1, 4], "30"];

Select[Range[2000], A044073Q] (* Paolo Xausa, Sep 24 2025 *)

CROSSREFS

Cf. A007090.

Sequence in context: A134618 A108405 A184838 * A044454 A098502 A158953

Adjacent sequences: A044070 A044071 A044072 * A044074 A044075 A044076