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 A269778 #8 Jan 29 2019 09:27:03 %S A269778 40,624,3816,15040,45600,115920,259504,527616,994680,1764400,2976600, %T A269778 4814784,7514416,11371920,16754400,24110080,33979464,47007216, %U A269778 63954760,85713600,113319360,147966544,191024016,244051200,308815000,387307440 %N A269778 Number of length-6 0..n arrays with every repeated value unequal to the previous repeated value plus one mod n+1. %H A269778 R. H. Hardin, <a href="/A269778/b269778.txt">Table of n, a(n) for n = 1..210</a> %F A269778 Empirical: a(n) = n^6 + 6*n^5 + 15*n^4 + 14*n^3 + 4*n^2. %F A269778 Conjectures from _Colin Barker_, Jan 29 2019: (Start) %F A269778 G.f.: 8*x*(5 + 43*x + 36*x^2 + 4*x^3 + 2*x^4) / (1 - x)^7. %F A269778 a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7. %F A269778 (End) %e A269778 Some solutions for n=3: %e A269778 ..3. .1. .3. .1. .1. .3. .3. .1. .2. .2. .3. .3. .0. .2. .1. .2 %e A269778 ..3. .0. .0. .3. .3. .3. .2. .2. .3. .2. .3. .0. .3. .0. .0. .3 %e A269778 ..1. .3. .0. .3. .3. .3. .0. .3. .2. .1. .3. .3. .3. .0. .0. .1 %e A269778 ..1. .2. .1. .0. .3. .3. .2. .3. .1. .1. .2. .0. .0. .0. .3. .0 %e A269778 ..2. .1. .2. .2. .3. .0. .1. .0. .2. .2. .3. .1. .2. .0. .0. .3 %e A269778 ..3. .2. .2. .2. .0. .1. .2. .3. .0. .1. .1. .1. .3. .3. .1. .0 %Y A269778 Row 6 of A269776. %K A269778 nonn %O A269778 1,1 %A A269778 _R. H. Hardin_, Mar 04 2016