cp's OEIS Frontend

A267236 Number of length-7 0..n arrays with no following elements greater than or equal to the first repeated value.

%I A267236 #8 Jan 10 2019 15:22:31
%S A267236 9,479,5646,34396,143695,469623,1291052,3121008,6830757,13811655,
%T A267236 26179802,47028540,80733835,133317583,212873880,330063296,498680193,
%U A267236 736298127,1064998374,1512186620,2111502855,2903829511,3938402884
%N A267236 Number of length-7 0..n arrays with no following elements greater than or equal to the first repeated value.
%H A267236 R. H. Hardin, <a href="/A267236/b267236.txt">Table of n, a(n) for n = 1..210</a>
%F A267236 Empirical: a(n) = n^7 + (69/20)*n^6 + (7/2)*n^5 + (7/6)*n^4 - (7/60)*n^2.
%F A267236 Conjectures from _Colin Barker_, Jan 10 2019: (Start)
%F A267236 G.f.: x*(9 + 407*x + 2066*x^2 + 2136*x^3 + 421*x^4 + x^5) / (1 - x)^8.
%F A267236 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 A267236 (End)
%e A267236 Some solutions for n=5:
%e A267236 ..3....0....1....1....0....1....0....4....1....5....1....0....1....4....1....3
%e A267236 ..1....3....5....3....5....2....4....3....0....3....5....2....5....1....0....0
%e A267236 ..0....0....3....4....0....5....3....2....5....5....5....5....5....0....2....4
%e A267236 ..1....4....0....1....2....3....2....5....1....3....1....3....4....3....0....5
%e A267236 ..4....5....1....3....1....0....4....5....3....1....1....1....4....1....3....5
%e A267236 ..5....3....2....4....0....1....3....2....4....3....3....0....2....4....2....2
%e A267236 ..2....2....2....3....5....2....1....2....4....1....3....2....0....0....4....3
%Y A267236 Row 7 of A267232.
%K A267236 nonn
%O A267236 1,1
%A A267236 _R. H. Hardin_, Jan 12 2016