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A198901
Number of n X 3 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.
2
2, 33, 1211, 50384, 2125425, 89793204, 3794115705, 160319061892, 6774239755817, 286243775060868, 12095158053422201, 511077834439270724, 21595464215307153225, 912510860892666556164, 38557914891188891686425
OFFSET
1,1
COMMENTS
Column 3 of A198906.
LINKS
FORMULA
Empirical: a(n) = 51*a(n-1) - 393*a(n-2) + 1013*a(n-3) - 902*a(n-4) + 232*a(n-5).
Empirical g.f.: x*(2 - 69*x + 314*x^2 - 434*x^3 + 139*x^4) / ((1 - x)*(1 - 5*x + 2*x^2)*(1 - 45*x + 116*x^2)). - Colin Barker, Mar 02 2018
EXAMPLE
Some solutions with values 0 to 4 for n=4:
..0..1..2....0..1..2....0..1..2....0..1..0....0..1..0....0..1..0....0..1..2
..1..0..3....1..3..1....2..3..1....1..0..2....2..3..2....2..0..3....2..3..1
..2..1..4....4..1..0....4..0..2....3..4..3....3..2..4....4..2..0....1..4..0
..4..0..3....2..0..2....0..1..3....1..2..1....2..1..0....3..0..4....3..0..4
CROSSREFS
Cf. A198906.
Sequence in context: A256278 A356953 A204239 * A242621 A206385 A263052
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 31 2011
STATUS
approved