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 A317761 #18 Dec 12 2021 02:23:10 %S A317761 16,42,52,72,109,177,302,532,955,1733,3164,5796,10637,19541,35918, %T A317761 66040,121443,223345,410772,755504,1389565,2555785,4700798,8646092, %U A317761 15902619,29249453,53798108,98950124,181997629,334745805,615693502,1132436880 %N A317761 Number of n X 5 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A317761 Column 5 of A317764. %H A317761 R. H. Hardin, <a href="/A317761/b317761.txt">Table of n, a(n) for n = 1..210</a> %F A317761 Empirical: a(n) = 2*a(n-1) - a(n-4) for n > 6. %e A317761 Some solutions for n=5: %e A317761 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 %e A317761 1 1 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 0 0 0 %e A317761 1 1 1 1 1 1 1 1 1 1 0 0 0 1 1 1 0 0 0 0 %e A317761 1 1 1 1 1 1 1 1 1 0 0 0 1 1 1 0 0 0 0 0 %e A317761 0 0 0 0 0 1 1 1 0 0 0 1 1 1 1 0 0 0 0 1 %Y A317761 Cf. A317764. %K A317761 nonn %O A317761 1,1 %A A317761 _R. H. Hardin_, Aug 06 2018