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 A265967 #4 Dec 19 2015 09:43:37 %S A265967 25,288,1504,7656,38096,190308,953072,4776628,23912032,119676172, %T A265967 599079504,2999395220,15015056688,75162919892,376276088880, %U A265967 1883701849404,9429821433376,47206168911396,236319556068624,1183033090841396 %N A265967 Number of nX2 0..4 arrays with the absolute differences of each element with its with horizontal and vertical neighbors unique. %C A265967 Column 2 of A265973. %H A265967 R. H. Hardin, <a href="/A265967/b265967.txt">Table of n, a(n) for n = 1..210</a> %F A265967 Empirical: a(n) = 8*a(n-2) +76*a(n-3) +219*a(n-4) -150*a(n-5) -2179*a(n-6) -6990*a(n-7) -7878*a(n-8) +14114*a(n-9) +97811*a(n-10) +209622*a(n-11) +139056*a(n-12) -409764*a(n-13) -1836900*a(n-14) -2835340*a(n-15) -1654712*a(n-16) +6180672*a(n-17) +17827872*a(n-18) +20705808*a(n-19) +4962208*a(n-20) -56431488*a(n-21) -79309568*a(n-22) -99599360*a(n-23) +85772288*a(n-24) +144689152*a(n-25) +353329152*a(n-26) -42172416*a(n-27) -139067392*a(n-28) -541589504*a(n-29) +2097152*a(n-30) +25165824*a(n-31) +301989888*a(n-32) for n>33 %e A265967 Some solutions for n=4 %e A265967 ..3..0....3..0....4..4....2..2....2..3....0..1....3..1....2..3....2..3....4..1 %e A265967 ..3..1....1..1....0..0....1..3....2..3....3..3....0..4....0..0....4..0....0..3 %e A265967 ..0..1....0..3....3..3....1..0....0..0....4..4....0..3....1..4....3..1....0..4 %e A265967 ..0..3....4..4....2..2....4..4....4..4....2..1....4..1....3..2....0..4....3..1 %Y A265967 Cf. A265973. %K A265967 nonn %O A265967 1,1 %A A265967 _R. H. Hardin_, Dec 19 2015