A268070 Number of nX2 0..3 arrays with every repeated value in every row and column unequal to the previous repeated value, and new values introduced in row-major sequential order.

2, 15, 159, 2191, 30295, 421471, 5797959, 79367143, 1079774311, 14630901175, 197520668295, 2659138662775, 35714778101863, 478783751931415, 6408527754114375, 85670414104756855, 1144076540594898727

Offset: 1

Author

R. H. Hardin, Jan 25 2016

Keywords

• nonn

Comments

Column 2 of A268073.

Examples

			Some solutions for n=5
..0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..1....0..1....0..1
..0..2....0..0....2..3....1..0....1..0....1..2....0..0....1..2....1..1....2..3
..2..1....1..2....2..3....2..0....1..1....0..3....2..2....1..3....2..3....2..2
..2..0....0..3....1..2....2..1....0..0....0..1....3..3....3..3....2..3....0..2
..1..0....1..1....0..2....0..2....2..3....1..2....1..2....0..0....3..1....3..3
		

Links

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

Crossrefs

Cf. A268073.

Formula

Empirical: a(n) = 26*a(n-1) -109*a(n-2) -1668*a(n-3) +10384*a(n-4) +30340*a(n-5) -193268*a(n-6) -33480*a(n-7) +882432*a(n-8) -461376*a(n-9) -1073088*a(n-10) +839808*a(n-11) for n>13