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 A245845 #6 Jul 23 2025 11:29:42 %S A245845 1,1,2,2,5,5,14,16,65,77,356,448,2279,2959,15572,20762,111641,151205, %T A245845 824798,1131376,6239399,8640935,48063692,67082670,375759443,527790821, %U A245845 2973583640,4198991910,23773324409,33722329677,191725694792,273021483730 %N A245845 Number of length n 0..2 arrays with new values introduced in order from both ends, and least squares fitting to a straight line with slope zero, with a single point taken as having zero slope. %C A245845 Column 2 of A245851 %H A245845 R. H. Hardin, <a href="/A245845/b245845.txt">Table of n, a(n) for n = 1..121</a> %e A245845 Some solutions for n=12 %e A245845 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 %e A245845 ..0....0....1....1....1....0....1....1....1....0....1....1....1....1....1....0 %e A245845 ..1....1....1....1....0....0....0....1....1....1....2....0....2....2....0....0 %e A245845 ..2....2....1....2....0....1....1....0....0....0....2....2....0....1....1....1 %e A245845 ..0....2....1....1....2....1....0....2....2....2....0....0....1....2....0....2 %e A245845 ..1....1....2....2....2....2....1....2....2....1....1....1....2....1....2....1 %e A245845 ..1....2....2....2....0....2....2....2....0....1....2....1....2....1....1....1 %e A245845 ..0....2....1....2....1....1....2....1....1....2....2....0....1....2....1....2 %e A245845 ..2....0....1....0....1....1....0....2....1....0....2....2....0....1....1....1 %e A245845 ..1....1....1....2....0....0....1....0....1....1....1....0....2....2....1....0 %e A245845 ..0....1....1....1....1....0....0....1....1....0....1....1....1....1....0....0 %e A245845 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 %K A245845 nonn %O A245845 1,3 %A A245845 _R. H. Hardin_, Aug 04 2014