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A220792
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Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..2 nX3 array
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1
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2, 19, 142, 1224, 9500, 74581, 568257, 4365491, 33310666, 254686655, 1943858975, 14845643699, 113333269572, 865350109627, 6606661069924, 50442027880390, 385116527587290, 2940337140545833, 22449121325990250, 171396892307878249
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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) = 13*a(n-1) -35*a(n-2) -145*a(n-3) +1022*a(n-4) -2050*a(n-5) -1549*a(n-6) +20179*a(n-7) -46292*a(n-8) +8272*a(n-9) +136479*a(n-10) -173216*a(n-11) -176296*a(n-12) +577186*a(n-13) +196578*a(n-14) -1945384*a(n-15) -548006*a(n-16) +8956828*a(n-17) -6927166*a(n-18) -16006326*a(n-19) +21244020*a(n-20) +31075832*a(n-21) -58929004*a(n-22) -71519712*a(n-23) +196957164*a(n-24) +72480220*a(n-25) -502328348*a(n-26) +113405724*a(n-27) +1032120188*a(n-28) -811288620*a(n-29) -1661363372*a(n-30) +2677972432*a(n-31) +1713915028*a(n-32) -6330143248*a(n-33) +725771184*a(n-34) +10612288116*a(n-35) -8206721280*a(n-36) -12118399464*a(n-37) +20654768280*a(n-38) +5122649968*a(n-39) -30045429504*a(n-40) +11631946112*a(n-41) +27880775680*a(n-42) -30641487616*a(n-43) -8057629056*a(n-44) +31841667840*a(n-45) -15245578240*a(n-46) -11794712064*a(n-47) +14747738112*a(n-48) +126064640*a(n-49) -4460855296*a(n-50) -1594695680*a(n-51) +4442669056*a(n-52) -766705664*a(n-53) -3195207680*a(n-54) +2537422848*a(n-55) -472907776*a(n-56) -295698432*a(n-57) +85983232*a(n-58) +29360128*a(n-59) for n>62
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EXAMPLE
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Some solutions for n=3
..0..0..0....1..0..1....0..1..1....0..1..1....1..1..0....1..1..0....1..1..0
..0..0..1....0..0..0....0..0..0....1..0..0....0..0..1....0..0..1....0..0..0
..0..1..0....0..1..1....1..1..0....0..0..0....0..0..0....0..1..0....1..1..0
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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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