A275347 Number of nX3 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,-2) and new values introduced in order 0..2.

5, 81, 288, 1024, 4100, 16956, 70272, 291320, 1211092, 5070832, 21255328, 89170864, 374453028, 1574982464, 6627474512, 27898519192, 117476409700, 494869331248, 2084962994672, 8785404327328, 37022705828932, 156033713723616

Offset: 1

Author

R. H. Hardin, Jul 24 2016

Keywords

• nonn

Comments

Column 3 of A275352.

Examples

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

Links

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

Crossrefs

Cf. A275352.

Formula

Empirical: a(n) = 4*a(n-1) +12*a(n-2) -48*a(n-3) +66*a(n-4) -210*a(n-5) -1120*a(n-6) +4028*a(n-7) -93*a(n-8) -4098*a(n-9) +27840*a(n-10) -78748*a(n-11) -37816*a(n-12) +204592*a(n-13) -97088*a(n-14) -576*a(n-15) +25984*a(n-16) -12544*a(n-17) for n>20