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 A212227 #6 Jun 02 2025 07:55:23 %S A212227 435,1113,2902,7596,19834,51440,131950,339564,876777,2267261,5864274, %T A212227 15159987,39161060,101136977,261240954,674934552,1743897567, %U A212227 4505828919,11641402990,30075908053,77701600604,200746256554,518645274018 %N A212227 Number of 0..2 arrays of length n+5 with sum no more than 6 in any length 6 subsequence (=50% duty cycle). %C A212227 Column 3 of A212232 %H A212227 R. H. Hardin, <a href="/A212227/b212227.txt">Table of n, a(n) for n = 1..210</a> %e A212227 Some solutions for n=3 %e A212227 ..1....0....2....1....1....1....1....0....2....0....2....2....2....0....0....0 %e A212227 ..0....0....1....1....2....1....0....1....0....1....0....0....2....1....0....0 %e A212227 ..0....2....0....1....1....2....0....0....2....0....1....0....0....0....1....0 %e A212227 ..0....0....1....1....1....0....1....2....0....0....2....2....1....0....1....0 %e A212227 ..2....2....0....0....0....1....2....2....1....1....0....0....1....2....0....0 %e A212227 ..1....0....2....0....0....1....1....0....0....1....1....2....0....1....2....2 %e A212227 ..0....1....1....1....2....0....0....0....0....1....2....1....2....0....0....2 %e A212227 ..1....0....1....1....0....2....0....0....0....0....0....0....1....1....1....1 %K A212227 nonn %O A212227 1,1 %A A212227 _R. H. Hardin_ May 06 2012