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A296877 Numbers n whose base-8 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. 4
65, 66, 67, 68, 69, 70, 71, 129, 130, 131, 132, 133, 134, 135, 138, 139, 140, 141, 142, 143, 193, 194, 195, 196, 197, 198, 199, 202, 203, 204, 205, 206, 207, 211, 212, 213, 214, 215, 257, 258, 259, 260, 261, 262, 263, 266, 267, 268, 269, 270, 271, 275, 276 (list; graph; refs; listen; history; text; internal format)
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 A296876-A296878 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-8 digits of 276 are 4,2,4; here #(pits) = 1 and #(peaks) = 0, so that 276 is in the sequence.

MATHEMATICA

z = 200; b = 8;

d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];

Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296876 *)

Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296877 *)

Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296878 *)

CROSSREFS

Cf. A296882, A296712, A296876, A296878.

Sequence in context: A299559 A130764 A043625 * A044875 A174928 A081647

Adjacent sequences:  A296874 A296875 A296876 * A296878 A296879 A296880

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Jan 09 2018

STATUS

approved

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Last modified October 26 21:33 EDT 2021. Contains 348269 sequences. (Running on oeis4.)