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A296890 Numbers whose base-12 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments. 4
168, 169, 180, 181, 182, 192, 193, 194, 195, 204, 205, 206, 207, 208, 216, 217, 218, 219, 220, 221, 228, 229, 230, 231, 232, 233, 234, 240, 241, 242, 243, 244, 245, 246, 247, 252, 253, 254, 255, 256, 257, 258, 259, 260, 264, 265, 266, 267, 268, 269, 270, 271 (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 A296888-A296890 partition the natural numbers. See the guides at A296712 and A296882.
LINKS
EXAMPLE
The base-12 digits of 24361 are 1,2,1,2,1; here #(pits) = 1 and #(peaks) = 2, so 24361 is in the sequence.
MATHEMATICA
z = 200; b = 12;
d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296888 *)
Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296889 *)
Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296890 *)
CROSSREFS
Sequence in context: A259086 A062518 A038823 * A225535 A333874 A045242
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Jan 10 2018
STATUS
approved

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