A043105 Numbers k such that 2 and 3 occur juxtaposed in the base-4 representation of k but not of k-1.

11, 14, 27, 30, 43, 56, 62, 75, 78, 91, 94, 107, 120, 126, 139, 142, 155, 158, 171, 203, 206, 219, 222, 224, 248, 254, 267, 270, 283, 286, 299, 312, 318, 331, 334, 347, 350, 363, 376, 382, 395, 398, 411, 414, 427, 459, 462, 475

Offset

1,1

Links

Table of n, a(n) for n=1..48.

Mathematica

Select[Range[500], MemberQ[Sort/@Partition[IntegerDigits[#, 4], 2, 1], {2, 3}]&&!MemberQ[Sort/@Partition[IntegerDigits[#-1, 4], 2, 1], {2, 3}]&]  (* Harvey P. Dale, Apr 21 2011 *)

Crossrefs

Cf. A007090.

Sequence in context: A030726 A039282 A045139 * A043885 A326916 A305010

Adjacent sequences: A043102 A043103 A043104 * A043106 A043107 A043108

Keyword

nonn,base

Author

Clark Kimberling

Status

approved