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A296892 Numbers 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
EXAMPLE
The base-13 digits of 59672 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so 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
Sequence in context: A013867 A074666 A043658 * A045002 A163556 A229467
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Jan 12 2018
STATUS
approved

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Last modified July 19 00:30 EDT 2024. Contains 374388 sequences. (Running on oeis4.)