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 A198712 #7 Jul 22 2025 13:05:25 %S A198712 14,1201,107042,9548295,851787199,75987485516,6778819400772, %T A198712 604736581320925,53948385378521909,4812720805166620356, %U A198712 429341516830025751982,38301440209010857426775,3416861087749979581617789 %N A198712 Number of nX5 0..3 arrays with values 0..3 introduced in row major order and no element equal to any horizontal or vertical neighbor. %C A198712 Column 5 of A198715 %H A198712 R. H. Hardin, <a href="/A198712/b198712.txt">Table of n, a(n) for n = 1..200</a> %F A198712 Empirical: a(n) = 119*a(n-1) -2929*a(n-2) +25066*a(n-3) -76115*a(n-4) -887*a(n-5) +324153*a(n-6) -444798*a(n-7) +175392*a(n-8) %e A198712 Some solutions with all values from 0 to 3 for n=4 %e A198712 ..0..1..2..0..2....0..1..2..3..1....0..1..0..2..0....0..1..2..0..1 %e A198712 ..1..0..3..2..3....1..0..3..1..0....1..0..1..0..1....1..0..1..2..3 %e A198712 ..0..1..2..3..1....0..1..2..3..2....0..1..2..1..3....0..1..0..3..1 %e A198712 ..1..3..0..2..3....1..2..1..2..1....1..3..0..3..2....1..0..2..1..0 %K A198712 nonn %O A198712 1,1 %A A198712 _R. H. Hardin_ Oct 29 2011