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A252252 Number of (n+2) X (6+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
616, 359, 318, 336, 366, 405, 453, 531, 633, 759, 963, 1230, 1560, 2094, 2793, 3657, 5055, 6885, 9147, 12807, 17598, 23520, 33102, 45645, 61149, 86235, 119073, 159663, 225339, 311310, 417576, 589518, 814593, 1092801, 1542951, 2132205, 2860563 (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*(616 - 257*x - 41*x^2 - 1830*x^3 + 801*x^4 + 162*x^5 + 610*x^6 - 269*x^7 - 56*x^8) / ((1 - x)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 6 of A252254.

Sequence in context: A268245 A268102 A190029 * A260367 A218847 A219426

Adjacent sequences:  A252249 A252250 A252251 * A252253 A252254 A252255

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 16 2014

STATUS

approved

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Last modified September 23 19:34 EDT 2021. Contains 347617 sequences. (Running on oeis4.)