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 A296323 #4 Dec 10 2017 11:44:30 %S A296323 1,8,23,61,185,562,1677,4998,14968,44818,134061,401123,1200360, %T A296323 3591843,10747770,32160619,96234620,287963368,861674203,2578393448, %U A296323 7715343389,23086669802,69082386936,206715662599,618556579000,1850910743566 %N A296323 Number of nX4 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 2 neighboring 1s. %C A296323 Column 4 of A296327. %H A296323 R. H. Hardin, <a href="/A296323/b296323.txt">Table of n, a(n) for n = 1..210</a> %F A296323 Empirical: a(n) = 4*a(n-1) -6*a(n-2) +13*a(n-3) -17*a(n-4) +22*a(n-5) -30*a(n-6) +33*a(n-7) -42*a(n-8) +37*a(n-9) -34*a(n-10) +21*a(n-11) -12*a(n-12) +4*a(n-13) -a(n-14) %e A296323 Some solutions for n=5 %e A296323 ..0..1..1..0. .1..1..0..0. .0..0..0..0. .0..1..1..0. .1..1..0..0 %e A296323 ..1..0..1..1. .1..0..0..0. .0..0..1..1. .0..1..0..0. .1..0..0..0 %e A296323 ..1..0..0..1. .0..0..0..0. .0..1..0..1. .0..0..1..1. .0..1..0..0 %e A296323 ..1..1..0..1. .0..0..0..1. .1..0..1..0. .0..0..1..0. .1..1..0..1 %e A296323 ..0..1..1..0. .0..0..1..1. .1..1..0..0. .0..0..0..0. .0..0..1..1 %Y A296323 Cf. A296327. %K A296323 nonn %O A296323 1,2 %A A296323 _R. H. Hardin_, Dec 10 2017