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 A296762 #7 Jan 22 2023 18:18:48 %S A296762 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,21,42,63,84,105,126, %T A296762 147,168,189,210,231,252,273,294,315,336,357,378,399,401,402,403,404, %U A296762 405,406,407,408,409,410,411,412,413,414,415,416,417,418,419,421 %N A296762 Numbers whose base-20 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments. %C A296762 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 A296762-A296764 partition the natural numbers. See the guide at A296712. %H A296762 Clark Kimberling, <a href="/A296762/b296762.txt">Table of n, a(n) for n = 1..10000</a> %e A296762 The base-20 digits of 421 are 1,1,1; here #(rises) = 0 and #(falls) = 0, so 421 is in the sequence. %t A296762 z = 200; b = 20; d[n_] := Sign[Differences[IntegerDigits[n, b]]]; %t A296762 Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296762 *) %t A296762 Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &] (* A296763 *) %t A296762 Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &] (* A296764 *) %Y A296762 Cf. A296763, A296764, A296712. %K A296762 nonn,base,easy %O A296762 1,2 %A A296762 _Clark Kimberling_, Jan 08 2018