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A252517 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 4 6 or 7 1
791, 432, 798, 1169, 2492, 5214, 9069, 20926, 45114, 80515, 188382, 409396, 733465, 1722606, 3755646, 6734185, 15840028, 34586990, 62035719, 146024522, 319084220, 572390435, 1347812928, 2946242464, 5285469629, 12447910092, 27215356622 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A252523

LINKS

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

FORMULA

Empirical: a(n) = 17*a(n-3) -90*a(n-6) +188*a(n-9) -184*a(n-12) +89*a(n-15) -21*a(n-18) +2*a(n-21) for n>24

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Sequence in context: A167587 A182387 A237735 * A263010 A351670 A282547

Adjacent sequences:  A252514 A252515 A252516 * A252518 A252519 A252520

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 18 2014

STATUS

approved

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Last modified October 2 23:51 EDT 2022. Contains 357230 sequences. (Running on oeis4.)