cp's OEIS Frontend

A221595 Number of 0..7 arrays of length n with each element differing from at least one neighbor by 1 or less.

%I A221595 #9 Oct 19 2017 06:12:15
%S A221595 0,22,62,484,2226,13056,67936,374342,2006006,10894988,58789204,
%T A221595 318224626,1719926984,9302621856,50297494954,271995651900,
%U A221595 1470758893578,7953136851900,43005796059376,232551746953140,1257506529312924
%N A221595 Number of 0..7 arrays of length n with each element differing from at least one neighbor by 1 or less.
%C A221595 Column 7 of A221596.
%H A221595 R. H. Hardin, <a href="/A221595/b221595.txt">Table of n, a(n) for n = 1..210</a>
%F A221595 Empirical: a(n) = 5*a(n-1) +3*a(n-2) -16*a(n-3) +65*a(n-4) -14*a(n-5) +23*a(n-6) +2*a(n-7) +8*a(n-8).
%F A221595 Empirical g.f.: 2*x^2*(11 - 24*x + 54*x^2 - 14*x^3 + 18*x^4 + 6*x^6) / (1 - 5*x - 3*x^2 + 16*x^3 - 65*x^4 + 14*x^5 - 23*x^6 - 2*x^7 - 8*x^8). - _Colin Barker_, Oct 19 2017
%e A221595 Some solutions for n=6
%e A221595 ..7....3....0....2....5....0....6....2....3....3....4....6....5....6....6....6
%e A221595 ..6....2....0....2....5....0....6....3....3....2....4....7....4....6....5....6
%e A221595 ..5....4....0....7....3....1....6....7....5....3....3....4....6....0....7....1
%e A221595 ..0....4....1....7....4....0....6....6....6....6....3....3....6....0....7....0
%e A221595 ..1....5....3....0....0....3....7....4....5....6....2....2....2....5....2....5
%e A221595 ..1....4....4....1....1....3....6....4....5....6....2....3....2....6....1....6
%K A221595 nonn
%O A221595 1,2
%A A221595 _R. H. Hardin_, Jan 20 2013