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A183437
Number of n X 4 binary arrays with every 1 having exactly one king-move neighbor equal to 1.
1
4, 28, 89, 361, 1620, 6392, 26243, 109483, 447624, 1841540, 7595029, 31226203, 128506736, 529054684, 2177033731, 8959709123, 36876424418, 151764857870, 624602187635, 2570631663169, 10579647127402, 43541564503936
OFFSET
1,1
COMMENTS
Column 4 of A183442.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 6*a(n-2) + 26*a(n-3) + 15*a(n-4) - 12*a(n-5) - 52*a(n-6) - 28*a(n-7) - 18*a(n-8) + 7*a(n-9).
Empirical g.f.: x*(4 + 24*x + 37*x^2 - 63*x^4 - 80*x^5 - 46*x^6 - 11*x^7 + 7*x^8) / (1 - x - 6*x^2 - 26*x^3 - 15*x^4 + 12*x^5 + 52*x^6 + 28*x^7 + 18*x^8 - 7*x^9). - Colin Barker, Mar 29 2018
EXAMPLE
Some solutions for 3 X 4:
..0..0..0..0....1..0..1..0....0..0..1..0....0..1..0..1....0..0..0..0
..0..0..1..0....1..0..1..0....1..0..1..0....0..1..0..1....1..0..1..0
..0..0..1..0....0..0..0..0....1..0..0..0....0..0..0..0....1..0..1..0
CROSSREFS
Cf. A183442.
Sequence in context: A361173 A005634 A183485 * A294315 A263239 A296015
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2011
STATUS
approved