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.
%I A296863 #11 Jan 22 2023 20:50:50 %S A296863 15,16,42,43,45,48,49,84,87,88,123,124,126,129,130,135,136,137,138, %T A296863 141,142,144,147,148,149,150,151,165,168,169,204,205,246,249,250,252, %U A296863 258,259,261,264,265,327,330,331,366,367,369,372,373,378,379,380,381,384 %N A296863 Numbers whose base-3 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments. %C A296863 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 A296861-A296863 partition the natural numbers. See the guides at A296882 and A296712. %H A296863 Clark Kimberling, <a href="/A296863/b296863.txt">Table of n, a(n) for n = 1..10000</a> %e A296863 The base-3 digits of 384 are 1, 1, 2, 0, 2, 0; here #(pits) = 1 and #(peaks) = 2, so 384 is in the sequence. %t A296863 z = 200; b = 3; %t A296863 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]]; %t A296863 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296861 *) %t A296863 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296862 *) %t A296863 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296863 *) %Y A296863 Cf. A296882, A296712, A296861, A296862. %K A296863 nonn,base,easy %O A296863 1,1 %A A296863 _Clark Kimberling_, Jan 09 2018