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 A268956 #4 Feb 16 2016 11:51:33 %S A268956 1,1,2,1,2,3,1,2,4,5,1,2,4,11,7,1,2,4,12,29,11,1,2,4,12,39,77,15,1,2, %T A268956 4,12,40,138,201,23,1,2,4,12,40,153,499,525,31,1,2,4,12,40,154,634, %U A268956 1830,1361,47,1,2,4,12,40,154,655,2785,6723,3525,63,1,2,4,12,40,154,656,3045 %N A268956 T(n,k)=Number of length-n 0..k arrays with no repeated value equal to the previous repeated value, with new values introduced in sequential order. %C A268956 Table starts %C A268956 ..1....1.....1.....1.....1.....1.....1.....1.....1.....1.....1.....1.....1 %C A268956 ..2....2.....2.....2.....2.....2.....2.....2.....2.....2.....2.....2.....2 %C A268956 ..3....4.....4.....4.....4.....4.....4.....4.....4.....4.....4.....4.....4 %C A268956 ..5...11....12....12....12....12....12....12....12....12....12....12....12 %C A268956 ..7...29....39....40....40....40....40....40....40....40....40....40....40 %C A268956 .11...77...138...153...154...154...154...154...154...154...154...154...154 %C A268956 .15..201...499...634...655...656...656...656...656...656...656...656...656 %C A268956 .23..525..1830..2785..3045..3073..3074..3074..3074..3074..3074..3074..3074 %C A268956 .31.1361..6723.12634.15124.15579.15615.15616.15616.15616.15616.15616.15616 %C A268956 .47.3525.24714.58409.78930.84572.85314.85359.85360.85360.85360.85360.85360 %H A268956 R. H. Hardin, <a href="/A268956/b268956.txt">Table of n, a(n) for n = 1..9999</a> %F A268956 Empirical for column k: %F A268956 k=1: a(n) = a(n-1) +2*a(n-2) -2*a(n-3) %F A268956 k=2: a(n) = 3*a(n-1) +2*a(n-2) -8*a(n-3) for n>5 %F A268956 k=3: a(n) = 6*a(n-1) -3*a(n-2) -30*a(n-3) +28*a(n-4) +36*a(n-5) -36*a(n-6) for n>8 %F A268956 k=4: [order 9] for n>11 %F A268956 k=5: [order 12] for n>14 %F A268956 k=6: [order 15] for n>17 %F A268956 k=7: [order 18] for n>20 %e A268956 Some solutions for n=8 k=4 %e A268956 ..0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0 %e A268956 ..1. .1. .1. .0. .1. .1. .1. .1. .1. .1. .1. .1. .1. .1. .1. .1 %e A268956 ..2. .2. .2. .1. .2. .2. .0. .1. .1. .2. .2. .2. .2. .0. .2. .2 %e A268956 ..2. .3. .2. .0. .3. .3. .2. .2. .2. .1. .2. .3. .1. .1. .0. .1 %e A268956 ..1. .4. .3. .2. .4. .2. .1. .3. .3. .3. .3. .1. .0. .2. .0. .3 %e A268956 ..1. .3. .4. .1. .4. .2. .3. .0. .3. .3. .3. .4. .2. .1. .3. .4 %e A268956 ..2. .2. .0. .2. .3. .4. .0. .1. .1. .1. .2. .0. .0. .2. .1. .2 %e A268956 ..0. .0. .0. .3. .1. .1. .3. .2. .4. .3. .1. .0. .0. .1. .0. .2 %Y A268956 Column 1 is A052955(n-1). %Y A268956 Column 2 is A267912. %Y A268956 Column 3 is A268069. %Y A268956 Diagonal is A268010. %K A268956 nonn,tabl %O A268956 1,3 %A A268956 _R. H. Hardin_, Feb 16 2016