A296863 Numbers whose base-3 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments.

15, 16, 42, 43, 45, 48, 49, 84, 87, 88, 123, 124, 126, 129, 130, 135, 136, 137, 138, 141, 142, 144, 147, 148, 149, 150, 151, 165, 168, 169, 204, 205, 246, 249, 250, 252, 258, 259, 261, 264, 265, 327, 330, 331, 366, 367, 369, 372, 373, 378, 379, 380, 381, 384

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 A296861-A296863 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-3 digits of 384 are 1, 1, 2, 0, 2, 0; here #(pits) = 1 and #(peaks) = 2, so 384 is in the sequence.

Mathematica

z = 200; b = 3;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296861 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296862 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296863 *)

Crossrefs

Cf. A296882, A296712, A296861, A296862.

Sequence in context: A041452 A041450 A042867 * A269459 A041462 A041464

Adjacent sequences: A296860 A296861 A296862 * A296864 A296865 A296866

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 09 2018

Status

approved