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 A296868 #11 Jan 22 2023 17:51:33 %S A296868 26,27,28,29,51,52,53,54,57,58,59,76,77,78,79,82,83,84,88,89,101,102, %T A296868 103,104,107,108,109,113,114,119,131,132,133,134,137,138,139,143,144, %U A296868 149,151,152,153,154,256,257,258,259,262,263,264,268,269,274,276,277 %N A296868 Numbers whose base-5 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. %C A296868 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 A296867-A296869 partition the natural numbers. See the guides at A296882 and A296712. %H A296868 Clark Kimberling, <a href="/A296868/b296868.txt">Table of n, a(n) for n = 1..10000</a> %e A296868 The base-5 digits of 277 are 2,1,0,2; here #(pits) = 1 and #(peaks) = 0, so 277 is in the sequence. %t A296868 z = 200; b = 5; %t A296868 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]]; %t A296868 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296867 *) %t A296868 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296868 *) %t A296868 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296869 *) %Y A296868 Cf. A296882, A296712, A296867, A296869. %K A296868 nonn,base,easy %O A296868 1,1 %A A296868 _Clark Kimberling_, Jan 09 2018