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 A269194 #4 Feb 20 2016 09:46:22 %S A269194 4,16,16,60,108,60,216,708,708,216,756,4476,9284,4476,756,2592,27684, %T A269194 115452,115452,27684,2592,8748,168252,1399612,2817548,1399612,168252, %U A269194 8748,29160,1008804,16629436,67134380,67134380,16629436,1008804,29160 %N A269194 T(n,k)=Number of nXk 0..3 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling three no more than once. %C A269194 Table starts %C A269194 ......4........16...........60.............216................756 %C A269194 .....16.......108..........708............4476..............27684 %C A269194 .....60.......708.........9284..........115452............1399612 %C A269194 ....216......4476.......115452.........2817548...........67134380 %C A269194 ....756.....27684......1399612........67134380.........3159954052 %C A269194 ...2592....168252.....16629436......1567933676.......145995171708 %C A269194 ...8748...1008804....194596516.....36068275268......6648192704604 %C A269194 ..29160...5983164...2249848972....819789099172....299224791093196 %C A269194 ..96228..35170980..25758552060..18452018423420..13339889117822420 %C A269194 .314928.205214268.292530733516.411983259384452.590022908205332548 %H A269194 R. H. Hardin, <a href="/A269194/b269194.txt">Table of n, a(n) for n = 1..219</a> %F A269194 Empirical for column k: %F A269194 k=1: a(n) = 6*a(n-1) -9*a(n-2) %F A269194 k=2: a(n) = 10*a(n-1) -21*a(n-2) -20*a(n-3) -4*a(n-4) for n>5 %F A269194 k=3: [order 8] for n>9 %F A269194 k=4: [order 16] for n>17 %F A269194 k=5: [order 40] for n>41 %e A269194 Some solutions for n=3 k=4 %e A269194 ..0..1..1..3. .0..0..2..2. .2..3..1..3. .1..3..1..1. .2..3..2..1 %e A269194 ..0..1..3..1. .2..0..0..2. .2..3..1..3. .1..1..1..3. .2..2..3..3 %e A269194 ..1..3..1..1. .2..0..2..0. .3..3..1..0. .0..3..1..3. .3..2..3..2 %Y A269194 Column 1 is A120926(n+1). %K A269194 nonn,tabl %O A269194 1,1 %A A269194 _R. H. Hardin_, Feb 20 2016