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A252110 Number of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7. 1
1600, 584, 776, 1314, 1956, 2658, 4488, 7248, 10632, 17952, 28992, 42528, 71808, 115968, 170112, 287232, 463872, 680448, 1148928, 1855488, 2721792, 4595712, 7421952, 10887168, 18382848, 29687808, 43548672, 73531392, 118751232 (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) = 4*a(n-3) for n>8.

Empirical g.f.: 2*x*(800 + 292*x + 388*x^2 - 2543*x^3 - 190*x^4 - 223*x^5 - 384*x^6 - 288*x^7) / (1 - 4*x^3). - Colin Barker, Dec 01 2018

EXAMPLE

Some solutions for n=4:

..2..1..3..2..2..3....2..1..0..1..2..3....0..1..2..3..2..2....1..0..1..1..0..2

..3..3..1..3..3..1....1..1..0..1..1..0....3..2..2..3..2..2....0..3..0..0..2..0

..2..2..3..2..2..3....0..0..2..0..0..3....0..3..3..1..3..3....1..0..1..1..0..1

..2..2..3..2..2..3....1..1..0..1..1..0....3..2..2..3..2..2....1..0..1..1..0..1

..3..3..1..3..3..0....2..1..0..1..1..0....3..2..2..3..2..1....0..2..0..0..2..0

..2..2..3..2..2..3....0..0..3..0..0..3....0..3..3..0..3..0....1..0..1..1..0..2

CROSSREFS

Column 4 of A252114.

Sequence in context: A084427 A260245 A282158 * A224951 A260499 A309562

Adjacent sequences:  A252107 A252108 A252109 * A252111 A252112 A252113

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 2014

STATUS

approved

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Last modified July 25 20:59 EDT 2021. Contains 346294 sequences. (Running on oeis4.)