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 A265930 #6 Dec 19 2015 09:51:01 %S A265930 25,340,1740,9016,44916,223788,1119424,5621396,28130560,140718764, %T A265930 704493864,3528165236,17658676752,88394841700,442557740144, %U A265930 2215472575772,11090095537400,55519269652292,277940545496176,1391364670745476 %N A265930 Number of 2Xn 0..4 arrays with the absolute differences of each element with its with horizontal and antidiagonal neighbors unique. %C A265930 Row 2 of A265928. %H A265930 R. H. Hardin, <a href="/A265930/b265930.txt">Table of n, a(n) for n = 1..210</a> %H A265930 R. H. Hardin, <a href="/A265930/a265930.txt">Empirical recurrence of order 55</a> %F A265930 Empirical recurrence of order 55 (see link above) %e A265930 Some solutions for n=4 %e A265930 ..0..4..4..3....3..2..4..3....3..1..0..4....4..4..0..1....1..1..3..3 %e A265930 ..2..1..3..0....2..0..3..2....1..3..4..0....3..0..1..4....2..0..0..4 %Y A265930 Cf. A265928. %K A265930 nonn %O A265930 1,1 %A A265930 _R. H. Hardin_, Dec 18 2015