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 A296905 #16 Jan 21 2023 02:23:13 %S A296905 440,441,460,461,462,480,481,482,483,500,501,502,503,504,520,521,522, %T A296905 523,524,525,540,541,542,543,544,545,546,560,561,562,563,564,565,566, %U A296905 567,580,581,582,583,584,585,586,587,588,600,601,602,603,604,605,606,607 %N A296905 Numbers whose base-20 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments. %C A296905 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 A296903..A296905 partition the natural numbers. See the guides at A296712 and A296882. %H A296905 Clark Kimberling, <a href="/A296905/b296905.txt">Table of n, a(n) for n = 1..10000</a> %e A296905 The base-20 digits of 176441 are 1,2,1,2,1; here #(pits) = 1 and #(peaks) = 2, so 176441 is in the sequence. %t A296905 z = 200; b = 20; %t A296905 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]]; %t A296905 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296903 *) %t A296905 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296904 *) %t A296905 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296905 *) %Y A296905 Cf. A296882, A296712, A296903, A296904. %K A296905 nonn,base,easy %O A296905 1,1 %A A296905 _Clark Kimberling_, Jan 12 2018 %E A296905 b-file replaced by _Clark Kimberling_, Feb 27 2018