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A183496
Half the number of nX3 0..2 arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors
1
4, 36, 256, 2088, 16512, 131072, 1048576, 8392704, 67113216, 536870912, 4295098368, 34359738368, 274877906944, 2199028248576, 17592186044416, 140737488355328, 1125900041060352, 9007199254740992, 72057594105298944
OFFSET
1,1
COMMENTS
Column 3 of A183501
LINKS
FORMULA
Empirical: a(n)=8*a(n-1)+32*a(n-3)-256*a(n-4)+160*a(n-5)-1280*a(n-6)-5120*a(n-8)+40960*a(n-9)-4096*a(n-10)+32768*a(n-11)+131072*a(n-13)-1048576*a(n-14)+532480*a(n-15)-4259840*a(n-16)-17039360*a(n-18)+136314880*a(n-19)-85196800*a(n-20)+681574400*a(n-21)+2726297600*a(n-23)-21810380800*a(n-24)+2181038080*a(n-25)-17448304640*a(n-26)-69793218560*a(n-28)+558345748480*a(n-29)-4294967296*a(n-30)+34359738368*a(n-31)+137438953472*a(n-33)-1099511627776*a(n-34)+687194767360*a(n-35)-5497558138880*a(n-36)-21990232555520*a(n-38)+175921860444160*a(n-39)-17592186044416*a(n-40)+140737488355328*a(n-41)+562949953421312*a(n-43)-4503599627370496*a(n-44)
EXAMPLE
Some solutions for 5X3
..1..1..2....0..0..2....0..2..1....0..1..0....0..2..0....0..1..2....0..0..2
..1..0..2....1..0..0....0..2..0....0..0..0....0..1..0....1..1..2....2..2..1
..1..1..2....0..0..0....0..1..1....2..1..2....1..1..1....1..2..0....2..1..1
..1..2..0....0..1..2....0..2..1....2..1..2....1..0..1....2..1..0....1..0..1
..2..2..0....0..1..2....0..2..2....0..0..0....1..2..2....2..1..0....1..1..1
CROSSREFS
Sequence in context: A202797 A294832 A075144 * A043024 A144889 A176097
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 05 2011
STATUS
approved