A275500 Number of nX4 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.

14, 324, 400, 656, 988, 2628, 7140, 19368, 52864, 144228, 394248, 1077956, 2947432, 8062396, 22050256, 60314412, 164976924, 451256880, 1234335036, 3376282048, 9235192524, 25261198432, 69097304872, 189003117812, 516983415672

Offset: 1

Author

R. H. Hardin, Jul 30 2016

Keywords

• nonn

Comments

Column 4 of A275504.

Examples

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

Links

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

Crossrefs

Cf. A275504.

Formula

Empirical: a(n) = a(n-1) +8*a(n-2) -28*a(n-4) -9*a(n-5) +55*a(n-6) +16*a(n-7) -70*a(n-8) -9*a(n-9) +56*a(n-10) -28*a(n-12) +a(n-13) +8*a(n-14) -a(n-16) for n>20