A274855 Number of n X 5 0..2 arrays with no element equal to any value at offset (-1,0) (0,-1) or (-2,-2) and new values introduced in order 0..2.

8, 81, 100, 330, 1085, 3602, 12102, 40901, 138307, 467309, 1578541, 5333233, 18021770, 60899601, 205786949, 695366607, 2349691060, 7939809084, 26829343060, 90658737265, 306343718596, 1035161871379, 3497901910024, 11819715442581

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 27*a(n-2) + 56*a(n-3) - 75*a(n-4) + 61*a(n-5) - 28*a(n-6) + 7*a(n-7) - a(n-8) for n>10.

Empirical g.f.: x*(8 + 17*x - 332*x^2 + 1269*x^3 - 2791*x^4 + 3819*x^5 - 3116*x^6 + 1441*x^7 - 373*x^8 + 54*x^9) / ((1 - x)^3*(1 - 5*x + 9*x^2 - 13*x^3 + 4*x^4 - x^5)). - Colin Barker, Jan 31 2019

Example

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

Crossrefs

Column 5 of A274858.

Sequence in context: A302625 A078292 A210134 * A301939 A302417 A227227

Adjacent sequences: A274852 A274853 A274854 * A274856 A274857 A274858

Keyword

nonn

Author

R. H. Hardin, Jul 09 2016

Status

approved