A275232 Number of 7Xn 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,0) and new values introduced in order 0..2.

32, 404, 8134, 164645, 3334854, 67550874, 1368326231, 27717164160, 561446064338, 11372797129197, 230370331746218, 4666441245648374, 94524645450606455, 1914715759242977500, 38784979537110927630, 785638615177198244373

Offset: 1

Author

R. H. Hardin, Jul 20 2016

Keywords

• nonn

Comments

Row 7 of A275228.

Examples

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

Links

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

Crossrefs

Cf. A275228.

Formula

Empirical: a(n) = 20*a(n-1) +57*a(n-2) -1206*a(n-3) +3096*a(n-4) +2306*a(n-5) -16957*a(n-6) +20440*a(n-7) -7755*a(n-8) for n>9