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 A249297 #6 Jul 23 2025 11:58:33 %S A249297 548,18232,237480,3164312,20626236,106687006,446465388,1564897170, %T A249297 4760601928,13086372374,32599885184,75623146588,164589989052, %U A249297 338640259244,663790705232,1250055198186,2264746878484,3971666747616 %N A249297 Number of length 7+3 0..n arrays with no four consecutive terms having the sum of any three elements equal to three times the fourth. %C A249297 Row 7 of A249290 %H A249297 R. H. Hardin, <a href="/A249297/b249297.txt">Table of n, a(n) for n = 1..210</a> %e A249297 Some solutions for n=2 %e A249297 ..0....0....0....0....1....0....0....1....1....0....2....1....0....0....1....0 %e A249297 ..0....2....1....1....2....0....0....0....1....0....2....0....0....2....0....2 %e A249297 ..2....0....0....0....2....0....1....2....2....2....1....2....0....1....0....0 %e A249297 ..1....1....0....2....2....2....0....0....2....0....1....2....2....2....1....2 %e A249297 ..2....0....2....0....0....0....1....0....0....1....2....0....0....1....2....1 %e A249297 ..1....2....1....0....1....0....0....1....0....2....2....1....0....2....0....2 %e A249297 ..2....0....0....2....2....1....2....0....2....0....2....2....2....1....2....2 %e A249297 ..0....2....2....0....2....0....2....2....0....0....0....0....0....1....0....2 %e A249297 ..2....0....2....2....1....2....1....2....2....1....2....0....0....2....0....0 %e A249297 ..2....0....1....2....1....0....2....2....1....1....2....1....0....2....2....1 %K A249297 nonn %O A249297 1,1 %A A249297 _R. H. Hardin_, Oct 24 2014