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A240296
Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of the elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4
1
2, 6, 26, 90, 340, 1194, 4424, 15766, 57754, 207500, 755822, 2726558, 9903504, 35798370, 129844290, 469823642, 1702892772, 6164774336, 22336556588, 80882514452, 293006418302, 1061132591102, 3843739599044, 13921096670132
OFFSET
1,1
COMMENTS
Row 2 of A240295
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +9*a(n-2) -23*a(n-3) -15*a(n-4) +30*a(n-5) +20*a(n-6) +7*a(n-7) -30*a(n-8) +a(n-9) +23*a(n-10) -8*a(n-11) -8*a(n-12)
EXAMPLE
Some solutions for n=4
..1..3..1..3....3..1..1..0....3..0..1..1....3..1..3..1....1..3..3..0
..1..0..0..0....3..0..0..1....3..0..1..2....3..0..2..2....1..2..2..3
CROSSREFS
Sequence in context: A213339 A317867 A092438 * A027207 A027231 A083845
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 03 2014
STATUS
approved