A296862 Numbers whose base-3 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

10, 11, 19, 20, 23, 31, 32, 35, 37, 38, 58, 59, 62, 64, 65, 71, 73, 74, 77, 91, 92, 93, 94, 95, 98, 100, 101, 104, 105, 106, 107, 112, 113, 116, 118, 119, 154, 155, 158, 172, 173, 174, 175, 176, 179, 181, 182, 185, 186, 187, 188, 193, 194, 197, 199, 200, 208

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 208 are 2, 1, 2, 0, 1; here #(pits) = 2 and #(peaks) = 1, so 208 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, A296863.

Sequence in context: A214897 A037307 A341820 * A225079 A214790 A191221

Adjacent sequences: A296859 A296860 A296861 * A296863 A296864 A296865

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 09 2018

Status

approved