A296877 Numbers whose base-8 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

65, 66, 67, 68, 69, 70, 71, 129, 130, 131, 132, 133, 134, 135, 138, 139, 140, 141, 142, 143, 193, 194, 195, 196, 197, 198, 199, 202, 203, 204, 205, 206, 207, 211, 212, 213, 214, 215, 257, 258, 259, 260, 261, 262, 263, 266, 267, 268, 269, 270, 271, 275, 276

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 A296876-A296878 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-8 digits of 276 are 4,2,4; here #(pits) = 1 and #(peaks) = 0, so 276 is in the sequence.

Mathematica

z = 200; b = 8;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296876 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296877 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296878 *)

Crossrefs

Cf. A296882, A296712, A296876, A296878.

Sequence in context: A299559 A130764 A043625 * A044875 A174928 A355313

Adjacent sequences: A296874 A296875 A296876 * A296878 A296879 A296880

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 09 2018

Status

approved