A296901 Numbers whose base-16 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 513, 514, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525, 526, 527, 530, 531, 532, 533, 534, 535, 536, 537, 538, 539, 540, 541, 542, 543, 769, 770, 771, 772, 773, 774, 775, 776

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 A296900-A296902 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-16 digits of 135698 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so 135698 is in the sequence.

Mathematica

z = 200; b = 16;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296900 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296901 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296902 *)

Crossrefs

Cf. A296882, A296712, A296900, A296902.

Sequence in context: A252726 A260679 A043676 * A045030 A253149 A139653

Adjacent sequences: A296898 A296899 A296900 * A296902 A296903 A296904

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 12 2018

Status

approved