A296883 Numbers whose base-10 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

101, 102, 103, 104, 105, 106, 107, 108, 109, 201, 202, 203, 204, 205, 206, 207, 208, 209, 212, 213, 214, 215, 216, 217, 218, 219, 301, 302, 303, 304, 305, 306, 307, 308, 309, 312, 313, 314, 315, 316, 317, 318, 319, 323, 324, 325, 326, 327, 328, 329, 401, 402

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 A296882-A296883 partition the natural numbers. See the guides at A296712 and A296882.

Links

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

Example

The base-10 digits of 21212 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so 21212 is in the sequence.

Mathematica

z = 200; b = 10;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296882 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296883 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296884 *)

Crossrefs

Cf. A296882, A296712, A296882, A296884.

Sequence in context: A138719 A043639 A152054 * A183086 A134808 A274612

Adjacent sequences: A296880 A296881 A296882 * A296884 A296885 A296886

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 10 2018

Status

approved