The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A296691 Numbers 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
EXAMPLE
The base-3 digits of 132 are 1,1,2,2,0; here #(rises) = #(falls) = 1, so 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
Sequence in context: A256624 A247324 A043706 * A028836 A028838 A178332
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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 26 01:16 EDT 2024. Contains 372807 sequences. (Running on oeis4.)