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A209379 1/4 the number of (n+1) X 6 0..2 arrays with every 2 X 2 subblock having distinct edge sums. 1
64, 170, 320, 1076, 2176, 8648, 18176, 78800, 168448, 758816, 1633280, 7474496, 16132096, 74296448, 160526336, 741182720, 1602101248, 7404724736, 16008396800, 74018886656, 160033570816, 740075522048, 1600134250496, 7400302039040 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A209382.

LINKS

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

FORMULA

Empirical: a(n) = 16*a(n-2) - 68*a(n-4) + 80*a(n-6).

Empirical g.f.: 2*x*(32 + 85*x - 352*x^2 - 822*x^3 + 704*x^4 + 1496*x^5) / ((1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 10*x^2)). - Colin Barker, Jul 09 2018

EXAMPLE

Some solutions for n=4:

..2..2..0..1..0..0....0..2..0..0..0..2....1..2..2..2..2..2....2..1..2..2..0..1

..0..1..0..2..2..1....1..2..1..2..1..2....0..0..1..0..1..0....2..0..0..1..0..2

..2..2..0..1..0..0....0..2..0..2..0..2....1..2..2..0..2..0....2..1..2..2..0..1

..0..1..0..2..2..1....0..1..0..1..0..1....0..0..1..0..1..0....2..0..0..1..0..2

..0..2..0..1..0..0....0..2..0..2..2..2....1..2..2..2..2..2....2..1..2..2..0..1

CROSSREFS

Cf. A209382.

Sequence in context: A044777 A251077 A228666 * A203448 A078093 A209371

Adjacent sequences:  A209376 A209377 A209378 * A209380 A209381 A209382

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 07 2012

STATUS

approved

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Last modified May 22 14:12 EDT 2022. Contains 353951 sequences. (Running on oeis4.)