A252387 - OEIS

A252387

Number of (3+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.

588, 529, 632, 663, 963, 1341, 1610, 2376, 3331, 4097, 6077, 8560, 10605, 15764, 22252, 27640, 41123, 58099, 72237, 107513, 151948, 188993, 281324, 397648, 494664, 736367, 1040899, 1294921, 1927685, 2724952, 3390021, 5046596, 7133860, 8875064

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-3) - 4*a(n-6) + a(n-9) for n>17.

Empirical g.f.: x*(588 + 529*x + 632*x^2 - 1689*x^3 - 1153*x^4 - 1187*x^5 + 1310*x^6 + 640*x^7 + 495*x^8 - 279*x^9 - 104*x^10 - 32*x^11 - 6*x^12 - 3*x^13 - 5*x^14 - 2*x^15 - x^16) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Row 3 of A252384.

Sequence in context: A003539 A064209 A113509 * A186395 A230716 A211852

Adjacent sequences: A252384 A252385 A252386 * A252388 A252389 A252390

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 17 2014

STATUS

approved