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 A268959 #4 Feb 16 2016 11:54:09 %S A268959 11,201,1830,12634,78930,485726,3068890,20245176,140084705,1016152035, %T A268959 7710817964,61062125594,503482001606,4313580168256,38328589616502, %U A268959 352618806519480,3353663975679253,32927374587977757,333319732346331654 %N A268959 Number of length-(n+5) 0..n arrays with no repeated value equal to the previous repeated value, with new values introduced in sequential order. %C A268959 Subdiagonal 5 of A268956. %H A268959 R. H. Hardin, <a href="/A268959/b268959.txt">Table of n, a(n) for n = 1..117</a> %e A268959 Some solutions for n=5 %e A268959 ..0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0. .0 %e A268959 ..1. .1. .0. .1. .1. .1. .1. .0. .1. .1. .0. .1. .1. .1. .1. .1 %e A268959 ..2. .0. .1. .1. .2. .0. .1. .1. .2. .2. .1. .2. .2. .2. .0. .2 %e A268959 ..1. .1. .1. .0. .3. .2. .2. .2. .0. .0. .2. .1. .1. .1. .1. .0 %e A268959 ..3. .2. .2. .2. .2. .3. .3. .3. .2. .3. .2. .3. .2. .3. .2. .3 %e A268959 ..1. .3. .2. .1. .4. .3. .4. .0. .3. .0. .1. .3. .1. .4. .1. .0 %e A268959 ..4. .1. .0. .3. .2. .0. .0. .2. .4. .4. .1. .4. .3. .4. .1. .1 %e A268959 ..1. .1. .0. .4. .4. .1. .5. .4. .0. .0. .0. .5. .4. .5. .3. .2 %e A268959 ..4. .3. .1. .4. .2. .4. .0. .4. .0. .5. .0. .2. .0. .2. .4. .0 %e A268959 ..1. .0. .3. .0. .0. .3. .5. .2. .5. .2. .3. .4. .4. .3. .5. .0 %Y A268959 Cf. A268956. %K A268959 nonn %O A268959 1,1 %A A268959 _R. H. Hardin_, Feb 16 2016