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 A302280 #7 Apr 05 2018 04:09:09 %S A302280 0,10,22,29,74,162,363,782,1766,3953,8784,19606,43887,98136,219234, %T A302280 490655,1098086,2457684,5502261,12323540,27604374,61847407,138600898, %U A302280 310664178,696450255,1561597724,3502013800,7854708637,17619975144 %N A302280 Number of 3 X n 0..1 arrays with every element equal to 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. %C A302280 Row 3 of A302278. %H A302280 R. H. Hardin, <a href="/A302280/b302280.txt">Table of n, a(n) for n = 1..210</a> %F A302280 Empirical: a(n) = 4*a(n-1) -4*a(n-2) +4*a(n-3) -7*a(n-4) -17*a(n-5) +29*a(n-6) -5*a(n-7) +24*a(n-8) +6*a(n-9) -75*a(n-10) +27*a(n-11) +16*a(n-12) +7*a(n-13) -8*a(n-14) -6*a(n-15) +6*a(n-16) for n>18 %e A302280 Some solutions for n=5: %e A302280 0 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0 1 0 %e A302280 1 1 0 1 1 0 1 0 0 1 0 1 1 1 0 0 0 1 0 1 %e A302280 1 0 1 0 1 1 1 0 1 1 1 0 1 0 1 0 1 1 1 1 %Y A302280 Cf. A302278. %K A302280 nonn %O A302280 1,2 %A A302280 _R. H. Hardin_, Apr 04 2018