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 A212236 #6 Jun 02 2025 07:56:18 %S A212236 70,775,7596,71427,660796,6062948,55360211,503916387,4577086146, %T A212236 41509589394,376014757137,3403088304192,30777595344747, %U A212236 278194559997967,2513387971773920,22698724065174107,204927838029912468 %N A212236 Number of 0..2 arrays of length 3+2*n with sum no more than 2*n in any length 2n subsequence (=50% duty cycle). %C A212236 Row 4 of A212232 %H A212236 R. H. Hardin, <a href="/A212236/b212236.txt">Table of n, a(n) for n = 1..210</a> %e A212236 Some solutions for n=3 %e A212236 ..1....0....1....0....1....0....0....0....1....1....2....2....0....2....0....0 %e A212236 ..0....2....2....2....2....2....0....1....0....2....1....1....2....0....0....0 %e A212236 ..0....1....0....0....1....0....1....2....0....0....1....0....0....0....2....2 %e A212236 ..2....0....0....2....0....1....1....1....2....2....1....1....0....0....0....2 %e A212236 ..0....2....1....0....0....0....0....0....1....0....0....2....0....1....0....1 %e A212236 ..1....0....1....0....1....1....0....1....0....0....1....0....0....2....0....0 %e A212236 ..1....1....0....2....0....0....1....0....1....0....0....0....2....1....2....0 %e A212236 ..1....1....2....1....0....2....1....1....0....2....1....0....2....1....0....1 %e A212236 ..0....1....1....0....1....0....2....1....1....0....2....1....2....0....2....1 %K A212236 nonn %O A212236 1,1 %A A212236 _R. H. Hardin_ May 06 2012