A252109 Number of (n+2) X (3+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7.

1568, 724, 554, 776, 1258, 1634, 2476, 3938, 5956, 9176, 14532, 22664, 35248, 55688, 88336, 138080, 217872, 348704, 546496, 861728, 1385536, 2174336, 3427392, 5523584, 8674048, 13670528, 22057216, 34649600, 54604032, 88154624, 138505216

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-3) - 8*a(n-6) for n>11.

Empirical g.f.: 2*x*(784 + 362*x + 277*x^2 - 4316*x^3 - 1543*x^4 - 845*x^5 + 5182*x^6 + 1091*x^7 + 292*x^8 + 264*x^9 + 484*x^10) / ((1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 01 2018

Example

Some solutions for n=4:
..0..3..3..1..3....2..0..1..1..0....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....0..2..0..0..2....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....1..0..1..1..0....3..1..3..3..0....1..3..3..0..3
..1..3..3..0..3....1..0..1..1..0....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....0..2..0..0..2....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....2..0..1..1..0....3..0..3..3..0....1..3..3..0..3

Crossrefs

Column 3 of A252114.

Sequence in context: A246734 A237467 A035890 * A045276 A099542 A232672

Adjacent sequences: A252106 A252107 A252108 * A252110 A252111 A252112

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved