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A233877 Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock having the sum of the squares of all six edge and diagonal differences equal to 11. 1
76, 300, 1224, 5156, 22020, 95464, 415092, 1819604, 7964808, 35055940, 153816132, 677977352, 2977325268, 13129922932, 57677272968, 254401366820, 1117656904164, 4930047668872, 21659909682612, 95545254192788, 419778763578888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + 19*a(n-2) - 60*a(n-3) + 8*a(n-4) + 36*a(n-5) - 12*a(n-6).

Empirical g.f.: 4*x*(19 + 18*x - 280*x^2 + 86*x^3 + 172*x^4 - 64*x^5) / ((1 - 3*x + x^2)*(1 - 20*x^2 + 12*x^4)). - Colin Barker, Oct 12 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 2 of A233883.

Sequence in context: A153676 A060316 A005571 * A067987 A167586 A234184

Adjacent sequences:  A233874 A233875 A233876 * A233878 A233879 A233880

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 17 2013

STATUS

approved

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Last modified October 26 22:19 EDT 2021. Contains 348269 sequences. (Running on oeis4.)