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 A240785 #6 Jul 23 2025 11:07:30 %S A240785 8,34,97,305,959,3033,9581,30354,96122,304551,964960,3057691,9689250, %T A240785 30704176,97298863,308333649,977091497,3096352093,9812187127, %U A240785 31094352992,98536547134,312257747281,989530396718,3135776321313,9937131194560 %N A240785 Number of 4Xn 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order. %C A240785 Row 4 of A240783 %H A240785 R. H. Hardin, <a href="/A240785/b240785.txt">Table of n, a(n) for n = 1..210</a> %F A240785 Empirical: a(n) = 6*a(n-1) -11*a(n-2) +7*a(n-3) -10*a(n-5) +13*a(n-6) -3*a(n-7) +27*a(n-8) -44*a(n-9) +13*a(n-10) +5*a(n-11) -8*a(n-12) +8*a(n-13) -3*a(n-14) +a(n-15) %e A240785 Some solutions for n=4 %e A240785 ..0..0..1..0....0..1..1..0....0..1..0..1....0..0..1..0....0..1..0..1 %e A240785 ..0..0..1..1....1..1..1..0....1..1..0..1....0..0..1..0....0..1..1..0 %e A240785 ..1..0..0..1....1..1..0..1....1..1..0..1....1..1..0..0....0..1..1..1 %e A240785 ..1..0..0..1....0..1..0..1....1..0..1..0....1..1..0..0....1..0..1..1 %K A240785 nonn %O A240785 1,1 %A A240785 _R. H. Hardin_, Apr 12 2014