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A239359
Number of n X 6 0..2 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 3.
1
7, 19, 39, 77, 156, 266, 409, 599, 852, 1191, 1635, 2213, 2944, 3837, 4910, 6178, 7657, 9363, 11312, 13520, 16003, 18777, 21858, 25262, 29005, 33103, 37572, 42428, 47687, 53365, 59478, 66042, 73073, 80587, 88600, 97128, 106187, 115793, 125962, 136710
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = (8/3)*n^3 - (45/2)*n^2 + (257/6)*n + 330 for n>13.
Conjectures from Colin Barker, Oct 26 2018: (Start)
G.f.: x*(7 - 9*x + 5*x^2 + 7*x^3 + 13*x^4 - 33*x^5 + 12*x^6 + 12*x^7 + 2*x^8 + 7*x^9 - 4*x^10 + 10*x^11 - 10*x^12 - 10*x^13 + 9*x^14 - 3*x^15 + x^16) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>17.
(End)
EXAMPLE
Some solutions for n=5:
..0..0..0..0..2..2....0..0..0..0..0..0....0..0..0..0..0..0....0..0..2..2..0..0
..0..0..0..2..2..1....0..0..0..0..0..0....0..0..0..0..0..2....0..0..2..1..2..2
..0..0..0..2..1..2....2..2..0..0..0..0....0..0..0..0..0..2....0..0..0..2..2..1
..0..0..0..0..2..2....2..1..2..2..0..0....2..2..0..0..0..0....0..0..0..2..1..2
..2..2..0..0..0..0....0..2..2..1..2..0....2..1..2..2..0..0....2..2..0..0..1..2
CROSSREFS
Column 6 of A239361.
Sequence in context: A108766 A303855 A295077 * A120720 A098422 A191066
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 17 2014
STATUS
approved