cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A296890 Numbers whose base-12 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments.

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%I A296890 #7 Jan 21 2023 18:16:56
%S A296890 168,169,180,181,182,192,193,194,195,204,205,206,207,208,216,217,218,
%T A296890 219,220,221,228,229,230,231,232,233,234,240,241,242,243,244,245,246,
%U A296890 247,252,253,254,255,256,257,258,259,260,264,265,266,267,268,269,270,271
%N A296890 Numbers whose base-12 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments.
%C A296890 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.
%H A296890 Clark Kimberling, <a href="/A296890/b296890.txt">Table of n, a(n) for n = 1..10000</a>
%e A296890 The base-12 digits of 24361 are 1,2,1,2,1; here #(pits) = 1 and #(peaks) = 2, so 24361 is in the sequence.
%t A296890 z = 200; b = 12;
%t A296890 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
%t A296890 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296888 *)
%t A296890 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296889 *)
%t A296890 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296890 *)
%Y A296890 Cf. A296882, A296712, A296888, A296889.
%K A296890 nonn,base,easy
%O A296890 1,1
%A A296890 _Clark Kimberling_, Jan 10 2018