|
%I #4 Dec 16 2012 17:52:33
%S 1,33,423,6156,87542,1250507,17847210,254759570,3636434730,
%T 51906768670,740920520709,10575949381405,150961805783944,
%U 2154838890134463,30758314061665953,439046226888854973,6266975132151978539
%N Number of ways to reciprocally link elements of an nX3 array either to themselves or to exactly two king-move neighbors
%C Column 3 of A220595
%H R. H. Hardin, <a href="/A220591/b220591.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 11*a(n-1) +46*a(n-2) +14*a(n-3) -46*a(n-4) -63*a(n-5) +35*a(n-6) +20*a(n-7) +a(n-8) -4*a(n-9) -a(n-10)
%e Some solutions for n=3 0=self 1=nw 2=n 3=ne 4=w 6=e 7=sw 8=s 9=se (reciprocal directions total 10)
%e .00.67.48...69.47.00...00.68.48...00.79.00...89.78.00...00.00.78...68.46.48
%e .38.89.28...38.18.00...00.29.28...39.68.14...23.12.00...00.37.27...28.79.28
%e .26.24.12...26.24.00...00.00.12...00.12.00...00.00.00...36.34.00...23.00.12
%K nonn
%O 1,2
%A _R. H. Hardin_ Dec 16 2012
| 