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 A196214 #7 Jun 02 2025 04:19:12 %S A196214 5,61,290,2161,14605,101780,723029,5056631,35105556,245353935, %T A196214 1720551401,12056500808,84351164429,589889437285,4128468776358, %U A196214 28906652171595,202358098703973,1416223455876968,9911711623472035,69377533372430719 %N A196214 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,1,2,4 for x=0,1,2,3,4. %C A196214 Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 2's, every 4 is next to 4 4's %C A196214 Column 4 of A196218 %H A196214 R. H. Hardin, <a href="/A196214/b196214.txt">Table of n, a(n) for n = 1..250</a> %e A196214 Some solutions for n=5 %e A196214 ..0..0..0..1....0..0..1..1....0..0..0..1....2..1..0..0....1..2..1..1 %e A196214 ..1..2..1..1....0..2..1..0....1..2..1..1....1..1..1..2....0..0..0..0 %e A196214 ..1..2..1..0....1..1..1..2....1..2..2..0....0..0..1..1....1..1..2..1 %e A196214 ..0..0..2..0....2..0..0..1....0..1..1..1....0..0..2..0....1..1..2..1 %e A196214 ..0..0..1..1....1..0..0..1....1..1..0..1....1..1..1..0....0..0..0..0 %K A196214 nonn %O A196214 1,1 %A A196214 _R. H. Hardin_ Sep 29 2011