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A296871 Numbers whose base-6 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. 4
37, 38, 39, 40, 41, 73, 74, 75, 76, 77, 80, 81, 82, 83, 109, 110, 111, 112, 113, 116, 117, 118, 119, 123, 124, 125, 145, 146, 147, 148, 149, 152, 153, 154, 155, 159, 160, 161, 166, 167, 181, 182, 183, 184, 185, 188, 189, 190, 191, 195, 196, 197, 202, 203 (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 A296870-A296872 partition the natural numbers. See the guides at A296882 and A296712.
LINKS
EXAMPLE
The base-6 digits of 203 are 5,3,5; here #(pits) = 1 and #(peaks) = 0, so 203 is in the sequence.
MATHEMATICA
z = 200; b = 6;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296870 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296871 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296872 *)
CROSSREFS
Sequence in context: A190839 A185698 A043611 * A346383 A337453 A071887
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Jan 09 2018
STATUS
approved

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Last modified February 22 02:45 EST 2024. Contains 370239 sequences. (Running on oeis4.)