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 A233176 #7 Oct 10 2018 08:30:03 %S A233176 11,80,2688,78336,2469888,76447744,2385772544,74291609600, %T A233176 2315406802944,72144847372288,2248141575290880,70053467808333824, %U A233176 2182930872087347200,68021929516908675072,2119621843032249204736,66049216835347669843968 %N A233176 Number of 3 X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs). %H A233176 R. H. Hardin, <a href="/A233176/b233176.txt">Table of n, a(n) for n = 1..210</a> %F A233176 Empirical: a(n) = 32*a(n-1) + 64*a(n-2) - 3072*a(n-3) + 8192*a(n-4) for n>5. %F A233176 Empirical g.f.: x*(11 - 272*x - 576*x^2 + 20992*x^3 - 53248*x^4) / ((1 - 8*x)*(1 - 24*x - 256*x^2 + 1024*x^3)). - _Colin Barker_, Oct 10 2018 %e A233176 Some solutions for n=4: %e A233176 ..0..1..0..4....0..1..5..2....0..1..0..2....0..1..0..1....0..1..2..1 %e A233176 ..5..1..5..2....5..1..0..4....3..1..5..1....2..1..5..4....5..1..0..4 %e A233176 ..0..4..5..2....3..1..0..4....2..1..5..1....5..1..0..1....5..4..5..1 %Y A233176 Row 3 of A233174. %K A233176 nonn %O A233176 1,1 %A A233176 _R. H. Hardin_, Dec 05 2013