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 A265969 #4 Dec 19 2015 09:45:10 %S A265969 340,7656,23920,74248,230784,721864,2263704,7152956,22522200,71566116, %T A265969 226074624,720236752,2280992736,7276115664,23077516368,73669330232, %U A265969 233938714232,747052012824,2374072906440,7582196847884,24110436293280 %N A265969 Number of nX4 0..4 arrays with the absolute differences of each element with its with horizontal and vertical neighbors unique. %C A265969 Column 4 of A265973. %H A265969 R. H. Hardin, <a href="/A265969/b265969.txt">Table of n, a(n) for n = 1..210</a> %e A265969 Some solutions for n=4 %e A265969 ..4..4..0..1....0..3..4..1....0..1..3..3....1..1..3..0....3..1..0..4 %e A265969 ..0..1..3..3....0..3..4..0....3..1..4..0....3..0..4..4....3..4..0..1 %e A265969 ..0..1..4..4....4..1..1..3....2..0..4..1....3..0..1..1....0..4..3..3 %e A265969 ..3..3..2..2....3..0..0..4....2..0..3..3....1..4..3..3....2..1..1..0 %Y A265969 Cf. A265973. %K A265969 nonn %O A265969 1,1 %A A265969 _R. H. Hardin_, Dec 19 2015