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 A261378 #4 Aug 17 2015 08:31:38 %S A261378 247,470,1714,5254,14312,42302,128998,377183,1099308,3261560,9647696, %T A261378 28358158,83587624,246835566,727709732,2144744412,6325797274, %U A261378 18656814748,55007382412,162201500248,478326263928,1410502041960,4159149074114 %N A261378 Number of (n+2)X(6+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101. %C A261378 Column 6 of A261380. %H A261378 R. H. Hardin, <a href="/A261378/b261378.txt">Table of n, a(n) for n = 1..210</a> %F A261378 Empirical: a(n) = a(n-2) +54*a(n-4) +147*a(n-6) -232*a(n-8) -760*a(n-10) +1201*a(n-12) +1735*a(n-14) -4951*a(n-16) +1746*a(n-18) +4365*a(n-20) -3877*a(n-22) -2176*a(n-24) +4748*a(n-26) -2239*a(n-28) +25*a(n-30) +151*a(n-32) +117*a(n-34) -35*a(n-36) -2*a(n-38) -a(n-40) for n>44 %e A261378 Some solutions for n=4 %e A261378 ..0..1..0..1..0..1..0..1....0..1..0..0..0..1..0..1....0..1..0..1..0..0..0..1 %e A261378 ..1..0..1..0..1..0..0..0....0..0..1..0..1..0..0..0....1..0..1..0..1..0..1..0 %e A261378 ..0..1..0..1..0..1..0..1....0..1..0..1..0..1..0..1....0..0..0..1..0..1..0..1 %e A261378 ..1..0..1..0..1..0..1..0....1..0..1..0..1..0..1..0....1..0..1..0..1..0..1..0 %e A261378 ..0..0..0..1..0..1..0..0....0..1..0..0..0..1..0..1....0..1..0..1..0..1..0..1 %e A261378 ..0..0..1..0..0..0..1..0....0..0..1..0..1..0..0..0....1..0..1..0..1..0..0..0 %Y A261378 Cf. A261380. %K A261378 nonn %O A261378 1,1 %A A261378 _R. H. Hardin_, Aug 17 2015