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 A249217 #5 Jul 23 2025 11:55:28 %S A249217 1952,80354,2363528,24619804,181549572,985612414,4386401650, %T A249217 16181960396,52677240496,151529682640,402510784944,980816185390, %U A249217 2256668468018,4888182757724,10136422535096 %N A249217 Number of length 5+6 0..n arrays with no seven consecutive terms having five times the sum of any two elements equal to two times the sum of the remaining five. %C A249217 Row 5 of A249212 %e A249217 Some solutions for n=2 %e A249217 ..1....0....0....0....1....1....2....1....2....0....1....1....1....1....0....0 %e A249217 ..0....0....2....0....0....1....1....2....2....0....1....1....1....2....2....0 %e A249217 ..0....1....0....0....2....2....1....1....2....1....1....0....2....0....0....1 %e A249217 ..1....0....2....2....1....1....1....1....1....0....2....1....1....1....0....2 %e A249217 ..0....0....2....1....0....1....1....0....2....1....2....0....2....0....0....2 %e A249217 ..1....0....2....1....1....2....2....2....2....2....2....0....2....2....1....2 %e A249217 ..0....2....1....2....0....2....1....2....0....0....1....1....2....2....0....2 %e A249217 ..0....1....2....0....0....0....2....2....1....0....1....2....2....1....0....1 %e A249217 ..1....1....0....2....1....2....1....2....0....0....0....1....1....2....1....0 %e A249217 ..2....2....2....2....1....1....2....0....2....1....1....0....2....2....1....0 %e A249217 ..1....2....0....1....1....0....0....0....2....0....2....1....1....0....1....1 %K A249217 nonn %O A249217 1,1 %A A249217 _R. H. Hardin_, Oct 23 2014