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!)
A296892 Numbers n whose base-13 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. 4
170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 522, 523, 524, 525, 526 (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 A296891-A296894 partition the natural numbers. See the guides at A296712 and A296882.

LINKS

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

EXAMPLE

The base-13 digits of 59672 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so that 59672 is in the sequence.

MATHEMATICA

z = 200; b = 13;

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

Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296891 *)

Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]    (* A296892 *)

Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]    (* A296893 *)

CROSSREFS

Cf. A296882, A296712, A296891, A296893.

Sequence in context: A013867 A074666 A043658 * A045002 A163556 A229467

Adjacent sequences:  A296889 A296890 A296891 * A296893 A296894 A296895

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Jan 12 2018

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 22 12:12 EST 2022. Contains 350481 sequences. (Running on oeis4.)