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 A296709 #7 Jan 27 2023 19:23:37 %S A296709 1,2,3,4,5,6,7,8,10,20,30,40,50,60,70,80,82,83,84,85,86,87,88,89,91, %T A296709 99,100,108,109,110,117,118,119,120,126,127,128,129,130,135,136,137, %U A296709 138,139,140,144,145,146,147,148,149,150,153,154,155,156,157,158 %N A296709 Numbers whose base-9 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments. %C A296709 A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296709-A296711 partition the natural numbers. See the guide at A296712. %H A296709 Clark Kimberling, <a href="/A296709/b296709.txt">Table of n, a(n) for n = 1..10000</a> %e A296709 The base-9 digits of 158 are 1,8,5; here #(rises) = 1 and #(falls) = 1, so 158 is in the sequence. %t A296709 z = 200; b = 9; d[n_] := Sign[Differences[IntegerDigits[n, b]]]; %t A296709 Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296709 *) %t A296709 Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &] (* A296710 *) %t A296709 Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &] (* A296711 *) %Y A296709 Cf. A296710, A296711, A296712. %K A296709 nonn,easy,base %O A296709 1,2 %A A296709 _Clark Kimberling_, Jan 08 2018