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A209378 1/4 the number of (n+1) X 5 0..2 arrays with every 2 X 2 subblock having distinct edge sums. 1
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 (list; graph; refs; listen; history; text; internal format)
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: A135269 A234140 A086047 * A182466 A234133 A203447

Adjacent sequences:  A209375 A209376 A209377 * A209379 A209380 A209381

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 07 2012

STATUS

approved

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Last modified September 24 23:43 EDT 2022. Contains 356951 sequences. (Running on oeis4.)