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A302226
Number of 3 X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
2
0, 11, 43, 164, 760, 3425, 15569, 70323, 318438, 1441136, 6522237, 29519913, 133601253, 604673484, 2736676090, 12385962613, 56057588893, 253711291691, 1148272314748, 5196968663084, 23520972129705, 106453623089577
OFFSET
1,2
COMMENTS
Row 3 of A302224.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +17*a(n-2) +12*a(n-3) -59*a(n-4) -83*a(n-5) +10*a(n-6) +87*a(n-7) +108*a(n-8) +22*a(n-9) -104*a(n-10) -71*a(n-11) +2*a(n-13) +a(n-14) +2*a(n-15) for n>17.
EXAMPLE
Some solutions for n=5
..0..0..1..0..0. .0..0..0..1..1. .0..0..0..0..1. .0..0..1..0..0
..1..0..1..1..0. .0..0..1..1..0. .1..1..0..1..0. .1..0..1..1..0
..1..1..0..0..1. .1..1..1..0..0. .1..1..1..0..1. .0..1..0..0..0
CROSSREFS
Cf. A302224.
Sequence in context: A196153 A373060 A213763 * A201714 A269422 A259798
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 03 2018
STATUS
approved