A296872 Numbers whose base-6 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments.

48, 49, 54, 55, 56, 60, 61, 62, 63, 66, 67, 68, 69, 70, 90, 91, 92, 96, 97, 98, 99, 102, 103, 104, 105, 106, 132, 133, 134, 135, 138, 139, 140, 141, 142, 174, 175, 176, 177, 178, 264, 265, 270, 271, 272, 276, 277, 278, 279, 282, 283, 284, 285, 286, 288, 294

Offset

1,1

Comments

A pit is an index i such that d(i-1) > d(i) < d(i+1); a peak is an index i such that d(i-1) < d(i) > d(i+1). The sequences A296870-A296872 partition the natural numbers. See the guides at A296882 and A296712.

Links

Clark Kimberling, Table of n, a(n) for n = 1..10000

Example

The base-6 digits of 294 are 1,2,1,0; here #(pits) = 0 and #(peaks) = 1, so 294 is in the sequence.

Mathematica

z = 200; b = 6;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296870 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296871 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296872 *)

Crossrefs

Cf. A296882, A296712, A296870, A296871.

Sequence in context: A121377 A327894 A332242 * A364702 A357429 A258694

Adjacent sequences: A296869 A296870 A296871 * A296873 A296874 A296875

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 09 2018

Status

approved