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 A185537 #9 Jul 22 2025 09:53:36 %S A185537 6,1155,127570,17526450,2241330570,295044602325,38418831900875, %T A185537 5024252800116630,655951718326130130,85695581922306489845, %U A185537 11192649881286988768850,1462013677990229903804335 %N A185537 1/6 the number of nX4 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors. %C A185537 Column 4 of A185540 %H A185537 R. H. Hardin, <a href="/A185537/b185537.txt">Table of n, a(n) for n = 1..48</a> %e A185537 Some solutions for 3X4 with a(1,1)=0 %e A185537 ..0..5..5..4....0..2..5..5....0..0..2..4....0..1..2..2....0..0..0..2 %e A185537 ..0..1..5..4....0..2..3..5....1..3..2..4....0..1..0..4....3..2..2..2 %e A185537 ..1..1..3..3....2..2..3..3....1..3..4..4....5..5..0..4....3..5..5..5 %K A185537 nonn %O A185537 1,1 %A A185537 _R. H. Hardin_ Jan 30 2011