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A252253 Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 3 5 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 3 5 6 or 7. 1
847, 437, 366, 384, 414, 453, 501, 579, 681, 807, 1011, 1278, 1608, 2142, 2841, 3705, 5103, 6933, 9195, 12855, 17646, 23568, 33150, 45693, 61197, 86283, 119121, 159711, 225387, 311358, 417624, 589566, 814641, 1092849, 1542999, 2132253, 2860611 (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) = a(n-1) + 3*a(n-3) - 3*a(n-4) - a(n-6) + a(n-7) for n>9.

Empirical g.f.: x*(847 - 410*x - 71*x^2 - 2523*x^3 + 1260*x^4 + 252*x^5 + 841*x^6 - 422*x^7 - 86*x^8) / ((1 - x)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 7 of A252254.

Sequence in context: A187861 A280484 A203335 * A247532 A235065 A268112

Adjacent sequences:  A252250 A252251 A252252 * A252254 A252255 A252256

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 16 2014

STATUS

approved

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Last modified October 24 05:38 EDT 2021. Contains 348217 sequences. (Running on oeis4.)