A296892 Numbers whose base-13 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 522, 523, 524, 525, 526

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 A296891-A296894 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-13 digits of 59672 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so 59672 is in the sequence.

Mathematica

z = 200; b = 13;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296891 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]    (* A296892 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]    (* A296893 *)

Crossrefs

Cf. A296882, A296712, A296891, A296893.

Sequence in context: A013867 A074666 A043658 * A045002 A163556 A229467

Adjacent sequences: A296889 A296890 A296891 * A296893 A296894 A296895

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 12 2018

Status

approved