login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A296693 Numbers n whose base-3 digits d(m), d(m-1), ... d(0) have #(rises) < #(falls); see Comments. 4
3, 6, 7, 9, 12, 18, 21, 22, 24, 25, 27, 30, 33, 34, 36, 39, 48, 54, 57, 60, 61, 63, 64, 65, 66, 67, 69, 70, 72, 75, 76, 78, 79, 81, 84, 87, 88, 90, 93, 99, 102, 103, 105, 106, 108, 111, 114, 115, 117, 120, 129, 144, 147, 156, 162, 165, 168, 169, 171, 174 (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 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 174 are 2,0,1,1,0; here #(rises) = 1 and #(falls) = 2, so that 174 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. A296691, A296692, A296712.

Sequence in context: A085359 A231664 A087916 * A282585 A280210 A023982

Adjacent sequences:  A296690 A296691 A296692 * A296694 A296695 A296696

KEYWORD

nonn,base

AUTHOR

Clark Kimberling, Dec 19 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 20 04:19 EST 2018. Contains 299358 sequences. (Running on oeis4.)