A044067 Numbers k such that string 1,2 occurs in the base 4 representation of k but not of k-1.

6, 22, 24, 38, 54, 70, 86, 88, 96, 118, 134, 150, 152, 166, 182, 198, 214, 216, 230, 246, 262, 278, 280, 294, 310, 326, 342, 344, 352, 374, 384, 454, 470, 472, 486, 502, 518, 534, 536, 550, 566, 582, 598, 600, 608, 630, 646, 662, 664, 678, 694, 710, 726, 728, 742, 758

Offset

1,1

Links

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

Mathematica

A044067Q[k_] := StringContainsQ[IntegerString[k, 4], "12"] && StringFreeQ[IntegerString[k - 1, 4], "12"];
Select[Range[2000], A044067Q] (* Paolo Xausa, Sep 25 2025 *)

Crossrefs

Cf. A007090.

Sequence in context: A084539 A034124 A055043 * A106685 A078118 A095411

Adjacent sequences: A044064 A044065 A044066 * A044068 A044069 A044070

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Sep 25 2025

Status

approved