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A302324
Number of 3 X n 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 25, 65, 177, 519, 1528, 4509, 13329, 39609, 117981, 351994, 1051660, 3146513, 9424435, 28252647, 84757174, 254424013, 764109856, 2295781145, 6900025071, 20743913296, 62377653458, 187606559148, 564330015524, 1697745322295, 5108065042362, 15370102161553, 46251622171599
OFFSET
1,1
COMMENTS
Row 3 of A302322.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) -4*a(n-2) -6*a(n-3) +a(n-4) -15*a(n-5) +25*a(n-6) +37*a(n-7) +8*a(n-8) -27*a(n-9) -57*a(n-10) -49*a(n-11) +51*a(n-12) +44*a(n-13) -12*a(n-14) for n>15.
EXAMPLE
Some solutions for n=5:
..0..0..0..1..1. .0..1..0..1..1. .0..0..0..1..0. .0..1..0..1..0
..0..1..0..1..0. .0..1..0..0..1. .1..1..1..1..0. .0..1..0..1..0
..0..1..0..1..0. .0..1..0..1..0. .0..0..0..1..0. .1..1..1..1..1
CROSSREFS
Cf. A302322.
Sequence in context: A368245 A212893 A376483 * A303017 A281339 A298282
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 05 2018
STATUS
approved