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 A249975 #8 Jun 02 2025 10:16:14 %S A249975 4,10,20,64,136,466,1012,3580,7864,28340,62696,228700,508400,1870466, %T A249975 4172660,15449740,34557400,128583340,288212440,1076603824,2417218544, %U A249975 9058241620,20366034760,76521687304,172247070064,648634854904 %N A249975 Number of length n+1 0..2*1 arrays with the sum of the absolute values of adjacent differences equal to n*1. %C A249975 Column 1 of A249982 %H A249975 R. H. Hardin, <a href="/A249975/b249975.txt">Table of n, a(n) for n = 1..210</a> %e A249975 Some solutions for n=6 %e A249975 ..1....0....1....0....0....0....1....2....0....1....0....0....2....0....0....0 %e A249975 ..2....1....2....0....2....2....1....1....0....2....2....1....0....1....1....0 %e A249975 ..0....2....1....1....1....1....0....2....1....0....1....2....2....0....1....0 %e A249975 ..1....1....1....0....0....2....2....2....0....0....2....2....1....1....0....2 %e A249975 ..0....2....0....1....1....1....0....0....2....1....2....1....1....0....2....1 %e A249975 ..1....1....2....2....1....0....0....0....0....2....0....0....0....1....2....0 %e A249975 ..1....0....1....0....2....0....1....2....0....1....0....2....0....2....0....2 %K A249975 nonn %O A249975 1,1 %A A249975 _R. H. Hardin_, Nov 10 2014