A209378 1/4 the number of (n+1) X 5 0..2 arrays with every 2 X 2 subblock having distinct edge sums.

32, 80, 156, 512, 1076, 4004, 8612, 33716, 73028, 291908, 633732, 2555588, 5552900, 22478852, 48859652, 198127364, 430707716, 1747864580, 3799906308, 15425772548, 33536978948, 136164892676, 296038014980, 1202040352772, 2613387280388

Offset

1,1

Comments

Column 4 of A209382.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 12*a(n-2) - 42*a(n-3) - 24*a(n-4) + 156*a(n-5) - 48*a(n-6) - 168*a(n-7) + 112*a(n-8).

Empirical g.f.: 4*x*(8 - 4*x - 117*x^2 + 107*x^3 + 449*x^4 - 472*x^5 - 502*x^6 + 548*x^7) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 12*x^2 + 28*x^4)). - Colin Barker, Jul 09 2018

Example

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

Crossrefs

Cf. A209382.

Sequence in context: A234140 A362044 A086047 * A182466 A234133 A203447

Adjacent sequences: A209375 A209376 A209377 * A209379 A209380 A209381

Keyword

nonn

Author

R. H. Hardin, Mar 07 2012

Status

approved