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 A229534 #9 Apr 27 2021 21:24:32 %S A229534 0,1,0,2,4,0,6,8,20,0,16,36,58,84,0,40,112,361,356,324,0,96,368,1588, %T A229534 3064,2038,1188,0,224,1152,7460,19276,24344,11184,4212,0,512,3568, %U A229534 33136,130854,221096,185808,59626,14580,0,1152,10880,146300,833108,2171944 %N A229534 T(n,k) = number of defective 3-colorings of an n X k 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order. %C A229534 Table starts %C A229534 .0.....1......2........6........16.........40...........96...........224 %C A229534 .0.....4......8.......36.......112........368.........1152..........3568 %C A229534 .0....20.....58......361......1588.......7460........33136........146300 %C A229534 .0....84....356.....3064.....19276.....130854.......833108.......5305746 %C A229534 .0...324...2038....24344....221096....2171944.....19965136.....184319130 %C A229534 .0..1188..11184...185808...2451728...34811238....463976296....6218438820 %C A229534 .0..4212..59626..1379512..26566266..544403948..10551803060..205336122417 %C A229534 .0.14580.311260.10036352.283010776.8359264560.236116939092.6668992563052 %H A229534 R. H. Hardin, <a href="/A229534/b229534.txt">Table of n, a(n) for n = 1..337</a> %F A229534 Empirical for column k: %F A229534 k=1: a(n) = a(n-1). %F A229534 k=2: a(n) = 6*a(n-1) - 9*a(n-2) for n > 3. %F A229534 k=3: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4) for n > 5. %F A229534 k=4: a(n) = 14*a(n-1) - 57*a(n-2) + 56*a(n-3) - 16*a(n-4) for n > 5. %F A229534 k=5: [order 12] for n > 13. %F A229534 k=6: [order 18] for n > 19. %F A229534 k=7: [order 38] for n > 39. %F A229534 Empirical for row n: %F A229534 n=1: a(n) = 4*a(n-1) - 4*a(n-2) for n > 4. %F A229534 n=2: a(n) = 4*a(n-1) - 8*a(n-3) - 4*a(n-4). %F A229534 n=3: a(n) = 6*a(n-1) - a(n-2) - 28*a(n-3) - 4*a(n-4) + 16*a(n-5) - 4*a(n-6) for n > 8. %F A229534 n=4: [order 12] for n > 14. %F A229534 n=5: [order 20] for n > 22. %F A229534 n=6: [order 46] for n > 48. %F A229534 n=7: [order 92] for n > 94. %e A229534 Some solutions for n=3, k=4: %e A229534 0 1 0 1 0 1 0 2 0 1 0 0 0 1 0 0 0 1 2 0 %e A229534 0 2 0 2 1 2 0 2 0 1 2 1 2 1 2 1 0 1 2 0 %e A229534 2 1 0 1 1 2 0 2 2 1 2 1 0 1 2 1 2 1 0 1 %Y A229534 Column 2 is A167682(n-1). %Y A229534 Row 1 is A057711(n-1). %K A229534 nonn,tabl %O A229534 1,4 %A A229534 _R. H. Hardin_, Sep 25 2013