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 A296901 #8 Jan 21 2023 02:23:20 %S A296901 257,258,259,260,261,262,263,264,265,266,267,268,269,270,271,513,514, %T A296901 515,516,517,518,519,520,521,522,523,524,525,526,527,530,531,532,533, %U A296901 534,535,536,537,538,539,540,541,542,543,769,770,771,772,773,774,775,776 %N A296901 Numbers whose base-16 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. %C A296901 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 A296900-A296902 partition the natural numbers. See the guides at A296712 and A296882. %H A296901 Clark Kimberling, <a href="/A296901/b296901.txt">Table of n, a(n) for n = 1..10000</a> %e A296901 The base-16 digits of 135698 are 2,1,2,1,2; here #(pits) = 2 and #(peaks) = 1, so 135698 is in the sequence. %t A296901 z = 200; b = 16; %t A296901 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]]; %t A296901 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296900 *) %t A296901 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296901 *) %t A296901 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296902 *) %Y A296901 Cf. A296882, A296712, A296900, A296902. %K A296901 nonn,base,easy %O A296901 1,1 %A A296901 _Clark Kimberling_, Jan 12 2018