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A252249 Number of (n+2) X (3+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
278, 242, 231, 249, 279, 318, 366, 444, 546, 672, 876, 1143, 1473, 2007, 2706, 3570, 4968, 6798, 9060, 12720, 17511, 23433, 33015, 45558, 61062, 86148, 118986, 159576, 225252, 311223, 417489, 589431, 814506, 1092714, 1542864, 2132118, 2860476 (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*(278 - 36*x - 11*x^2 - 816*x^3 + 138*x^4 + 72*x^5 + 272*x^6 - 48*x^7 - 26*x^8) / ((1 - x)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 02 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

..2..2..0..2..2....2..0..0..2..0....0..2..0..0..2....2..0..2..2..0

CROSSREFS

Column 3 of A252254.

Sequence in context: A189609 A264371 A154231 * A257368 A056995 A228135

Adjacent sequences:  A252246 A252247 A252248 * A252250 A252251 A252252

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 16 2014

STATUS

approved

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Last modified November 30 13:47 EST 2021. Contains 349420 sequences. (Running on oeis4.)