|
%I #8 May 17 2018 17:02:14
%S 2,15,40,103,202,381,636,1033,1550,2287,3212,4451,5946,7869,10140,
%T 12969,16238,20211,24744,30147,36222,43349,51296,60493,70646,82267,
%U 95016,109467,125206,142897,162076,183477,206546,232123,259596,289879,322262
%N Number of 0..n arrays x(0..4) of 5 elements with zero 4th difference.
%C Row 5 of A200154.
%H R. H. Hardin, <a href="/A200156/b200156.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = a(n-1) +a(n-2) +a(n-4) -3*a(n-5) -a(n-6) +a(n-8) +3*a(n-9) -a(n-10) -a(n-12) -a(n-13) +a(n-14).
%F Empirical g.f.: x*(2 + 13*x + 23*x^2 + 48*x^3 + 57*x^4 + 67*x^5 + 60*x^6 + 48*x^7 + 26*x^8 + 11*x^9 + x^10 - x^12 + x^13) / ((1 - x)^5*(1 + x)^3*(1 + x^2)^2*(1 + x + x^2)). - _Colin Barker_, May 17 2018
%e Some solutions for n=6:
%e ..6....4....1....0....2....6....2....2....4....6....6....0....6....6....2....4
%e ..4....5....1....6....0....1....2....3....6....2....5....6....6....5....3....4
%e ..1....3....1....6....2....0....0....2....3....0....2....6....4....4....2....5
%e ..0....1....2....4....4....2....0....1....0....0....1....3....3....4....2....5
%e ..4....2....5....4....2....6....6....2....2....2....6....0....6....6....6....2
%Y Cf. A200154.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 13 2011
|
