A274746 Number of n X 5 0..2 arrays with no element equal to any value at offset (-1,-2) (0,-1) or (-1,0) and new values introduced in order 0..2.

8, 60, 518, 4554, 40242, 355504, 3140840, 27748676, 245154340, 2165891856, 19135242632, 169056228008, 1493579612136, 13195491722256, 116579658950800, 1029959107782112, 9099492769592768, 80392287459022000, 710250565228311920

Offset: 1

Author

R. H. Hardin, Jul 04 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 5 of A274749.

Formula

Empirical: a(n) = 9*a(n-1) - 14*a(n-3) + 10*a(n-4) - 2*a(n-5) for n>6.

Empirical g.f.: 2*x*(4 - 6*x - 11*x^2 + 2*x^3 + 8*x^4 - 3*x^5) / (1 - 9*x + 14*x^3 - 10*x^4 + 2*x^5). - Colin Barker, Jan 30 2019