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A296691 Numbers n whose base-3 digits d(m), d(m-1), ... d(0) have #(rises) = #(falls); see Comments. 4
1, 2, 4, 8, 10, 11, 13, 15, 16, 19, 20, 23, 26, 28, 29, 31, 35, 37, 38, 40, 42, 43, 45, 49, 51, 52, 55, 56, 58, 62, 68, 71, 73, 74, 77, 80, 82, 83, 85, 89, 91, 92, 94, 96, 97, 100, 101, 104, 107, 109, 110, 112, 116, 118, 119, 121, 123, 124, 126, 130, 132 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296691-A296693 partition the natural numbers. See the guide at A296712.

LINKS

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

EXAMPLE

The base-3 digits of 132 are 1,1,2,2,0; here #(rises) = #(falls) = 1, so that 132 is in the sequence.

MATHEMATICA

z = 200; b = 3; d[n_] := Sign[Differences[IntegerDigits[n, b]]];

Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296691 *)

Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296692 *)

Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296693 *)

CROSSREFS

Cf. A296692, A296693, A296712.

Sequence in context: A256624 A247324 A043706 * A028836 A028838 A178332

Adjacent sequences:  A296688 A296689 A296690 * A296692 A296693 A296694

KEYWORD

nonn,base

AUTHOR

Clark Kimberling, Dec 19 2017

STATUS

approved

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Last modified June 15 16:13 EDT 2019. Contains 324142 sequences. (Running on oeis4.)