cp's OEIS Frontend

A268945 Number of length-4 0..n arrays with no repeated value unequal to the previous repeated value plus one mod n+1.

%I A268945 #8 Jan 17 2019 04:20:43
%S A268945 10,63,220,565,1206,2275,3928,6345,9730,14311,20340,28093,37870,49995,
%T A268945 64816,82705,104058,129295,158860,193221,232870,278323,330120,388825,
%U A268945 455026,529335,612388,704845,807390,920731,1045600,1182753,1332970
%N A268945 Number of length-4 0..n arrays with no repeated value unequal to the previous repeated value plus one mod n+1.
%H A268945 R. H. Hardin, <a href="/A268945/b268945.txt">Table of n, a(n) for n = 1..210</a>
%F A268945 Empirical: a(n) = n^4 + 4*n^3 + 3*n^2 + n + 1.
%F A268945 Conjectures from _Colin Barker_, Jan 17 2019: (Start)
%F A268945 G.f.: x*(10 + 13*x + 5*x^2 - 5*x^3 + x^4) / (1 - x)^5.
%F A268945 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
%F A268945 (End)
%e A268945 Some solutions for n=9:
%e A268945 ..9. .3. .4. .0. .0. .7. .3. .6. .2. .7. .3. .0. .7. .6. .5. .7
%e A268945 ..2. .7. .5. .9. .0. .5. .4. .7. .8. .8. .9. .8. .0. .3. .7. .2
%e A268945 ..6. .2. .3. .7. .8. .9. .9. .7. .3. .6. .6. .8. .8. .8. .9. .7
%e A268945 ..2. .5. .2. .4. .9. .7. .3. .2. .5. .0. .2. .9. .7. .1. .1. .9
%Y A268945 Row 4 of A268944.
%K A268945 nonn
%O A268945 1,1
%A A268945 _R. H. Hardin_, Feb 16 2016