

A252725


Number of (6+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.


1



165, 154, 170, 178, 214, 262, 270, 354, 434, 466, 622, 790, 846, 1170, 1490, 1618, 2254, 2902, 3150, 4434, 5714, 6226, 8782, 11350, 12366, 17490, 22610, 24658, 34894, 45142, 49230, 69714, 90194, 98386, 139342, 180310, 196686, 278610, 360530, 393298
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OFFSET

1,1


LINKS



FORMULA

Empirical: a(n) = a(n1) +3*a(n3) +3*a(n4) 2*a(n6) 2*a(n7) for n>9.
Empirical g.f.: x*(165 + 319*x + 324*x^2  147*x^3  565*x^4  496*x^5  182*x^6 + 86*x^7 + 8*x^8) / ((1  x)*(1 + x)*(1 + x + x^2)*(1  2*x^3)).  Colin Barker, Dec 06 2018


EXAMPLE

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


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



