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 A249191 #6 Jul 23 2025 11:52:43 %S A249191 1792,4586,11874,30876,80354,208876,541624,1400008,3618986,9363890, %T A249191 24245852,62802512,162682626,421350312,1091065338,2824952300, %U A249191 7314373948,18939413676,49042889408,126997380012,328860987784,851576753420 %N A249191 Number of length n+6 0..2 arrays with no seven consecutive terms having four times the sum of any three elements equal to three times the sum of the remaining four. %C A249191 Column 2 of A249197 %H A249191 R. H. Hardin, <a href="/A249191/b249191.txt">Table of n, a(n) for n = 1..210</a> %e A249191 Some solutions for n=5 %e A249191 ..0....0....1....2....1....2....2....2....2....1....2....1....2....2....0....0 %e A249191 ..0....0....0....1....2....1....1....2....0....1....0....0....0....0....2....1 %e A249191 ..1....1....1....0....2....1....2....1....2....1....2....1....2....0....0....2 %e A249191 ..1....1....2....2....1....2....2....1....0....0....1....1....2....0....0....2 %e A249191 ..0....2....2....2....2....1....0....0....2....2....1....0....0....0....2....1 %e A249191 ..0....0....2....2....2....2....1....1....1....2....2....1....0....2....2....0 %e A249191 ..1....1....0....2....0....1....0....2....1....2....2....1....2....1....2....2 %e A249191 ..1....1....2....1....1....2....0....2....2....1....2....0....2....1....0....1 %e A249191 ..2....2....1....1....0....0....1....2....0....0....2....1....2....1....2....1 %e A249191 ..0....2....1....0....2....2....1....2....2....2....0....0....2....1....0....2 %e A249191 ..1....2....1....0....2....2....0....0....2....1....1....0....2....2....2....2 %K A249191 nonn %O A249191 1,1 %A A249191 _R. H. Hardin_, Oct 23 2014