A222161 - OEIS

%I #4 Feb 10 2013 09:27:41

%S 13,57,205,733,2627,9305,32576,113448,394406,1369551,4750768,16468347,

%T 57064823,197691644,684764755,2371639753,8213463074,28443621204,

%U 98498816070,341089856906,1181139073972,4090059069992,14163013655470

%N Number of (n+3)X1 arrays of occupancy after each element moves up to +-3 places but not 0 and without 2-loops

%C Column 3 of A222165

%H R. H. Hardin, <a href="/A222161/b222161.txt">Table of n, a(n) for n = 1..45</a>

%F Empirical: a(n) = 7*a(n-1) -13*a(n-2) -3*a(n-3) +21*a(n-4) -41*a(n-6) +83*a(n-7) +30*a(n-8) -216*a(n-9) +17*a(n-10) +214*a(n-11) -19*a(n-12) -101*a(n-13) +5*a(n-14) -9*a(n-15) -5*a(n-16) +45*a(n-17) -12*a(n-18) -21*a(n-19) +2*a(n-20) +a(n-21)

%e Some solutions for n=3

%e ..0....0....0....0....0....2....1....0....1....1....0....1....0....1....0....2

%e ..2....0....0....0....0....2....0....0....1....2....0....3....0....1....0....0

%e ..2....2....4....0....1....2....1....1....4....2....0....1....3....0....1....0

%e ..1....1....1....2....2....0....2....3....0....0....3....1....2....2....1....2

%e ..0....1....0....2....2....0....2....0....0....1....1....0....1....2....2....1

%e ..1....2....1....2....1....0....0....2....0....0....2....0....0....0....2....1

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 10 2013