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 A296883 Numbers n whose base-10 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. 3

%I

%S 101,102,103,104,105,106,107,108,109,201,202,203,204,205,206,207,208,

%T 209,212,213,214,215,216,217,218,219,301,302,303,304,305,306,307,308,

%U 309,312,313,314,315,316,317,318,319,323,324,325,326,327,328,329,401,402

%N Numbers n whose base-10 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments.

%C 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 A296882-A296883 partition the natural numbers. See the guides at A296712 and A296882.

%H Clark Kimberling, <a href="/A296883/b296883.txt">Table of n, a(n) for n = 1..10000</a>

%e The base-10 digits of 21212 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so that 21212 is in the sequence.

%t z = 200; b = 10;

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

%t Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296882 *)

%t Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296883 *)

%t Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296884 *)

%Y Cf. A296882, A296712, A296882, A296884.

%K nonn,base,easy

%O 1,1

%A _Clark Kimberling_, Jan 10 2018

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Last modified September 16 08:14 EDT 2021. Contains 347469 sequences. (Running on oeis4.)