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A204285
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Number of (n+2)X3 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly two different ways, and new values 0..3 introduced in row major order
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1
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738, 9747, 142107, 1429921, 17355817, 221925179, 2543715910, 30734237265, 375949277297, 4450811814117, 53643615196610, 648002350392040, 7749991491871620, 93261925199990577, 1122526895349202427
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 9*a(n-1) +27*a(n-2) +664*a(n-3) -6017*a(n-4) -10999*a(n-5) -27927*a(n-6) +785208*a(n-7) +1808986*a(n-8) -9291216*a(n-9) -58864836*a(n-10) +70625144*a(n-11) +839548244*a(n-12) +1742144344*a(n-13) -13053421089*a(n-14) -45209996819*a(n-15) +97520505233*a(n-16) +523248475740*a(n-17) +147069819085*a(n-18) -3565977566421*a(n-19) -6389085726125*a(n-20) +14574941056086*a(n-21) +54876011291376*a(n-22) -16219581437292*a(n-23) -293541619810656*a(n-24) -323579212113040*a(n-25) +667840461578684*a(n-26) +1966778355137184*a(n-27) +708881353209528*a(n-28) -4015657851215328*a(n-29) -6256887254376432*a(n-30) +2667648411207600*a(n-31) +18811035543808080*a(n-32) +16070283734174784*a(n-33) -25105573528212096*a(n-34) -65077248129557760*a(n-35) -28905229739428992*a(n-36) +67903636498057728*a(n-37) +75044327559497280*a(n-38) -51792823644377472*a(n-39) -107101927689807744*a(n-40) +33654399508194048*a(n-41) +173449321804016640*a(n-42) +94399670897897472*a(n-43) -69991374374203392*a(n-44) -120205352519700480*a(n-45) -39583908650041344*a(n-46) +23935898566656000*a(n-47) +11472182752739328*a(n-48) -1747834315997184*a(n-49) -394955387043840*a(n-50)
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EXAMPLE
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Some solutions for n=3
..0..0..0....0..0..0....0..0..0....0..0..1....0..0..1....0..0..1....0..1..0
..1..0..1....0..1..2....0..0..0....1..1..0....2..0..3....0..2..1....0..0..1
..0..2..1....3..3..3....1..2..1....1..1..1....1..0..0....1..1..1....0..2..1
..1..1..1....1..1..1....0..0..0....0..2..1....0..0..0....0..3..1....0..0..0
..2..1..1....3..3..1....1..1..1....1..0..1....2..3..0....0..2..1....0..2..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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