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A296711 Numbers n whose base-9 digits d(m), d(m-1), ..., d(0) have #(rises) < #(falls); see Comments. 4
9, 18, 19, 27, 28, 29, 36, 37, 38, 39, 45, 46, 47, 48, 49, 54, 55, 56, 57, 58, 59, 63, 64, 65, 66, 67, 68, 69, 72, 73, 74, 75, 76, 77, 78, 79, 81, 90, 162, 171, 172, 180, 181, 243, 252, 253, 261, 262, 263, 270, 271, 272, 324, 333, 334, 342, 343, 344, 351 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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 A296709-A296711 partition the natural numbers. See the guide at A296712.

LINKS

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

EXAMPLE

The base-9 digits of 351 are 4,3,0; here #(rises) = 0 and #(falls) = 2, so that 351 is in the sequence.

MATHEMATICA

z = 200; b = 9; d[n_] := Sign[Differences[IntegerDigits[n, b]]];

Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296709 *)

Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296710 *)

Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296711 *)

CROSSREFS

Cf. A296709, A296710, A296712.

Sequence in context: A202188 A060993 A297267 * A297144 A107977 A257226

Adjacent sequences:  A296708 A296709 A296710 * A296712 A296713 A296714

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Jan 08 2018

STATUS

approved

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Last modified June 23 01:31 EDT 2021. Contains 345394 sequences. (Running on oeis4.)