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_R. H. Hardin (rhhardin(AT)att.net) _ Oct 16 2011
editing
approved
R. H. Hardin, <a href="/A197643/b197643.txt">Table of n, a(n) for n = 1..200</a>
allocated Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,2,0,2 for Ron Hardinx=0,1,2,3,4
1, 11, 82, 342, 1649, 9007, 49381, 256485, 1303838, 6775152, 35730226, 187160271, 972480937, 5058363340, 26414032504, 137991741860, 719704308772, 3751431869467, 19565984801032, 102090380933252, 532589325917487
1,2
Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 2's, every 3 is next to 3 0's, every 4 is next to 4 2's
Column 3 of A197648
Empirical: a(n) = 3*a(n-1) +22*a(n-3) +162*a(n-4) +207*a(n-5) +40*a(n-6) -199*a(n-7) -964*a(n-8) -1725*a(n-9) -4618*a(n-10) +565*a(n-11) +1265*a(n-12) +854*a(n-13) -504*a(n-14) +24*a(n-15)
Some solutions for n=4
..0..0..1....0..1..1....2..2..1....0..0..0....0..0..0....0..0..1....1..2..2
..0..2..2....1..2..2....2..2..0....1..2..2....0..1..0....0..2..2....1..2..2
..0..2..2....0..2..2....1..1..0....1..2..2....0..2..2....0..2..2....0..0..0
..0..0..1....0..0..0....0..0..0....0..0..0....0..2..2....0..1..0....0..3..0
allocated
nonn
R. H. Hardin (rhhardin(AT)att.net) Oct 16 2011
approved
editing
allocated for Ron Hardin
allocated
approved