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A195965
Number of nX4 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to itself
1
1, 1, 7, 21, 48, 118, 222, 527, 1370, 3336, 7717, 17897, 41296, 98631, 236602, 554717, 1304489, 3078621, 7242849, 17138388, 40496052, 95320672, 224944921, 530817100, 1251705990, 2954749967, 6970501275, 16438448824, 38788768683, 91508873268
OFFSET
1,3
COMMENTS
Column 4 of A195969
LINKS
FORMULA
Empirical: a(n) = 6*a(n-3) +2*a(n-4) +19*a(n-5) +32*a(n-6) +22*a(n-7) +2*a(n-8) -31*a(n-9) +42*a(n-10) -133*a(n-11) -145*a(n-12) -88*a(n-13) -150*a(n-14) +149*a(n-15) -444*a(n-16) +236*a(n-17) +468*a(n-18) +54*a(n-19) +350*a(n-20) +126*a(n-21) +804*a(n-22) -1320*a(n-24) +640*a(n-25) +384*a(n-26) -704*a(n-27) for n>29
EXAMPLE
Some solutions for n=5
..1..1..0..1....0..2..2..2....2..2..2..0....2..2..2..2....2..2..2..2
..2..2..2..1....2..2..0..2....2..0..2..2....2..1..1..2....2..0..1..2
..2..1..2..2....2..1..1..2....2..1..0..2....2..2..0..2....2..2..1..2
..2..1..0..2....2..2..2..2....2..1..2..2....1..2..2..2....1..2..0..2
..2..2..2..2....0..1..1..0....2..2..2..0....1..0..1..1....1..2..2..2
CROSSREFS
Sequence in context: A146802 A147054 A146629 * A137182 A011927 A163723
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 25 2011
STATUS
approved