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A198523
Number of nX3 0..4 arrays with values 0..4 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors
2
5, 193, 16714, 1877316, 222590953, 26670041125, 3201911378187, 384557171168810, 46189600128813487, 5547962760669962158, 666383179391895903794, 80041410904141273707361, 9614030302463648373863365
OFFSET
1,1
COMMENTS
Column 3 of A198528
LINKS
FORMULA
Empirical: a(n) = 140*a(n-1) -2296*a(n-2) -11502*a(n-3) +41183*a(n-4) +408760*a(n-5) +595837*a(n-6) -3718654*a(n-7) -13795951*a(n-8) -11064332*a(n-9) +29075688*a(n-10) +108107068*a(n-11) +134930012*a(n-12) -37607560*a(n-13) -266631136*a(n-14) -319325600*a(n-15) -322970496*a(n-16) -229207424*a(n-17) +130810368*a(n-18) +389159424*a(n-19) +272935936*a(n-20) +65761280*a(n-21) -8192000*a(n-22) -6356992*a(n-23) -786432*a(n-24) for n>25
EXAMPLE
Some solutions for n=4
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..1
..1..2..1....1..2..0....0..1..2....1..2..3....0..1..2....1..2..1....0..0..2
..3..0..0....3..2..4....2..1..3....4..0..2....2..0..2....3..0..3....3..1..1
..1..4..0....3..0..3....2..3..0....0..2..3....2..1..3....1..4..0....2..1..1
CROSSREFS
Sequence in context: A240702 A240639 A198482 * A093154 A194572 A068793
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 26 2011
STATUS
approved