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 A196707 #7 Jun 22 2022 11:21:46 %S A196707 1,2,2,4,11,4,6,38,38,6,12,136,207,136,12,22,488,1366,1366,488,22,40, %T A196707 1744,8672,16676,8672,1744,40,74,6208,55436,193326,193326,55436,6208, %U A196707 74,136,22202,353591,2264381,4114365,2264381,353591,22202,136,250,79292 %N A196707 T(n,k) = Number of n X k 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,1,0,4,2 for x=0,1,2,3,4. %C A196707 Every 0 is next to 0 3's, every 1 is next to 1 1's, every 2 is next to 2 0's, every 3 is next to 3 4's, every 4 is next to 4 2's. %C A196707 Table starts %C A196707 ...1......2........4...........6.............12...............22 %C A196707 ...2.....11.......38.........136............488.............1744 %C A196707 ...4.....38......207........1366...........8672............55436 %C A196707 ...6....136.....1366.......16676.........193326..........2264381 %C A196707 ..12....488.....8672......193326........4114365.........88057485 %C A196707 ..22...1744....55436.....2264381.......88057485.......3444722540 %C A196707 ..40...6208...353591....26495227.....1883754015.....134682461126 %C A196707 ..74..22202..2257739...310276380....40313628190....5269250186071 %C A196707 .136..79292.14423220..3632827590...862817869506..206166859931473 %C A196707 .250.282984.92115943.42527506151.18466264182264.8065792226445503 %H A196707 R. H. Hardin, <a href="/A196707/b196707.txt">Table of n, a(n) for n = 1..144</a> %e A196707 Some solutions for n=6, k=4 %e A196707 ..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..1....0..0..0..0 %e A196707 ..0..0..0..1....0..0..0..0....0..0..0..1....0..0..0..1....0..0..0..0 %e A196707 ..0..1..2..1....1..1..0..2....2..2..0..2....0..1..2..0....0..0..0..0 %e A196707 ..0..1..0..0....0..2..0..1....0..1..1..0....0..1..2..0....2..2..0..0 %e A196707 ..0..0..0..0....1..1..0..1....2..0..2..2....2..0..0..0....0..1..1..0 %e A196707 ..2..0..0..0....0..0..0..0....1..1..0..0....1..1..2..0....0..2..0..0 %K A196707 nonn,tabl %O A196707 1,2 %A A196707 _R. H. Hardin_, Oct 05 2011