%I #4 Aug 16 2013 08:59:41
%S 21,271,2731,23351,176851,1225631,8006491,50556551,313882531,
%T 1932641711,11839990891,72260648471,439667406451,2668522016831,
%U 16163719991611,97745259402791,590286253682371,3560791008422351,21460113482174731
%N Number of second differences of arrays of length n+2 of numbers in 0..5
%C Column 5 of A228218
%H R. H. Hardin, <a href="/A228215/b228215.txt">Table of n, a(n) for n = 1..189</a>
%F Empirical: a(n) = 11*a(n-1) -30*a(n-2) for n>11
%e Some solutions for n=4
%e ..1....2...-1...-7...-4..-10...-6....1....2....8...-3....2...-6...-3....5....6
%e .-4....2...-3....5....0....8....5....2...-5...-2....1...-2....8....0...-3...-9
%e ..1...-2...-1...-1....7...-3....2....0....4...-3....4....6...-1....3...-1....5
%e ..5....3....6....2...-5...-2...-3....5....3....5...-8...-5...-5...-1....6....3
%K nonn
%O 1,1
%A _R. H. Hardin_ Aug 16 2013