cp's OEIS Frontend

A268948 Number of length-7 0..n arrays with no repeated value unequal to the previous repeated value plus one mod n+1.

%I A268948 #8 Jan 17 2019 05:14:30
%S A268948 30,969,9684,54045,213042,667065,1773384,4171869,8925990,17704137,
%T A268948 33006300,58441149,99058554,161742585,255670032,392839485,588676014,
%U A268948 862716489,1239380580,1748832477,2427938370,3321324729,4482542424
%N A268948 Number of length-7 0..n arrays with no repeated value unequal to the previous repeated value plus one mod n+1.
%H A268948 R. H. Hardin, <a href="/A268948/b268948.txt">Table of n, a(n) for n = 1..210</a>
%F A268948 Empirical: a(n) = n^7 + 7*n^6 + 6*n^5 + 10*n^4 + 4*n^3 + n^2 + 4*n - 3.
%F A268948 Conjectures from _Colin Barker_, Jan 17 2019: (Start)
%F A268948 G.f.: 3*x*(10 + 243*x + 924*x^2 + 675*x^3 - 110*x^4 - 55*x^5 - 8*x^6 + x^7) / (1 - x)^8.
%F A268948 a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.
%F A268948 (End)
%e A268948 Some solutions for n=4:
%e A268948 ..4. .2. .4. .3. .1. .1. .2. .0. .1. .4. .4. .2. .4. .2. .3. .3
%e A268948 ..1. .0. .0. .1. .3. .0. .0. .1. .3. .4. .0. .3. .3. .2. .0. .4
%e A268948 ..3. .4. .2. .3. .2. .3. .4. .0. .2. .1. .2. .3. .3. .0. .3. .0
%e A268948 ..0. .4. .0. .0. .1. .2. .2. .4. .4. .4. .4. .2. .4. .3. .1. .0
%e A268948 ..4. .0. .3. .2. .1. .3. .3. .0. .1. .0. .2. .3. .2. .0. .0. .1
%e A268948 ..3. .1. .1. .3. .4. .1. .1. .0. .2. .2. .4. .4. .0. .3. .2. .4
%e A268948 ..1. .4. .2. .1. .2. .1. .2. .3. .4. .4. .2. .1. .2. .4. .3. .1
%Y A268948 Row 7 of A268944.
%K A268948 nonn
%O A268948 1,1
%A A268948 _R. H. Hardin_, Feb 16 2016