A241126 Number of nX3 0..2 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..2 introduced in row major order.

4, 54, 723, 9773, 132369, 1792237, 24269723, 328645291, 4450319537, 60263615333, 816054461063, 11050530322615, 149639792084929, 2026334190350265, 27439427668181531, 371568616043522567, 5031563999805819365

Offset: 1

Author

R. H. Hardin, Apr 16 2014

Keywords

• nonn

Comments

Column 3 of A241130

Examples

			Some solutions for n=4
..0..1..1....0..1..1....0..1..0....0..1..0....0..1..2....0..1..0....0..1..0
..1..0..0....2..0..2....2..0..1....1..0..2....0..2..1....0..2..1....1..2..0
..0..2..1....1..0..2....1..0..1....0..1..0....1..0..2....1..2..1....0..1..1
..1..2..0....2..1..1....2..1..0....2..1..2....2..0..1....0..1..2....1..2..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 14*a(n-1) -7*a(n-2) +27*a(n-3) -170*a(n-4) -631*a(n-5) -1135*a(n-6) +5278*a(n-7) -3113*a(n-8) +5125*a(n-9) +13678*a(n-10) -10325*a(n-11) +15744*a(n-12) -52520*a(n-13) -13756*a(n-14) -110176*a(n-15) +64424*a(n-16) -53672*a(n-17) -13552*a(n-18) +87456*a(n-19) -198528*a(n-20) +71552*a(n-21) -44288*a(n-22) -116224*a(n-23) -4096*a(n-24) -122880*a(n-25) -65536*a(n-26)