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 A296862 #11 Jan 22 2023 20:50:40 %S A296862 10,11,19,20,23,31,32,35,37,38,58,59,62,64,65,71,73,74,77,91,92,93,94, %T A296862 95,98,100,101,104,105,106,107,112,113,116,118,119,154,155,158,172, %U A296862 173,174,175,176,179,181,182,185,186,187,188,193,194,197,199,200,208 %N A296862 Numbers whose base-3 digits d(m), d(m-1), ..., d(0) have #(pits) > #(peaks); see Comments. %C A296862 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 A296861-A296863 partition the natural numbers. See the guides at A296882 and A296712. %H A296862 Clark Kimberling, <a href="/A296862/b296862.txt">Table of n, a(n) for n = 1..10000</a> %e A296862 The base-3 digits of 208 are 2, 1, 2, 0, 1; here #(pits) = 2 and #(peaks) = 1, so 208 is in the sequence. %t A296862 z = 200; b = 3; %t A296862 d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]]; %t A296862 Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &] (* A296861 *) %t A296862 Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &] (* A296862 *) %t A296862 Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &] (* A296863 *) %Y A296862 Cf. A296882, A296712, A296861, A296863. %K A296862 nonn,base,easy %O A296862 1,1 %A A296862 _Clark Kimberling_, Jan 09 2018