

A296893


Numbers n whose base13 digits d(m), d(m1), ..., d(0) have #(pits) < #(peaks); see Comments.


4



195, 196, 208, 209, 210, 221, 222, 223, 224, 234, 235, 236, 237, 238, 247, 248, 249, 250, 251, 252, 260, 261, 262, 263, 264, 265, 266, 273, 274, 275, 276, 277, 278, 279, 280, 286, 287, 288, 289, 290, 291, 292, 293, 294, 299, 300, 301, 302, 303, 304, 305, 306
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OFFSET

1,1


COMMENTS

A pit is an index i such that d(i1) > d(i) < d(i+1); a peak is an index i such that d(i1) < d(i) > d(i+1). The sequences A296891A296894 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 base13 digits of 33151 are 1,2,1,2,1; here #(pits) = 1 and #(peaks) = 2, so that 33151 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, A296892.
Sequence in context: A281807 A220160 A183583 * A045073 A204811 A234814
Adjacent sequences: A296890 A296891 A296892 * A296894 A296895 A296896


KEYWORD

nonn,base,easy


AUTHOR

Clark Kimberling, Jan 12 2018


STATUS

approved



