A275567 Number of 4Xn 0..2 arrays with no element equal to any value at offset (-2,0) (-1,2) or (0,-2) and new values introduced in order 0..2.

6, 216, 504, 1176, 3192, 8664, 23712, 64896, 180960, 504600, 1418100, 3985350, 11202990, 31492086, 88441764, 248378136, 697381260, 1958065350, 5498516310, 15440588646, 43363859406, 121784495766, 342029032494, 960580887846

Offset

1,1

Comments

Row 4 of A275565.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -35*a(n-3) +31*a(n-4) +131*a(n-5) -205*a(n-6) -254*a(n-7) +705*a(n-8) -6*a(n-9) -1218*a(n-10) +823*a(n-11) +1150*a(n-12) -1646*a(n-13) -439*a(n-14) +1789*a(n-15) -394*a(n-16) -1015*a(n-17) +499*a(n-18) +285*a(n-19) -205*a(n-20) -46*a(n-21) +51*a(n-22) -6*a(n-24) +a(n-25) for n>28

Example

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

Crossrefs

Cf. A275565.

Sequence in context: A332989 A370128 A030265 * A007221 A195802 A145249

Adjacent sequences: A275564 A275565 A275566 * A275568 A275569 A275570

Keyword

nonn

Author

R. H. Hardin, Aug 01 2016

Status

approved