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A060336
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Number of n X n {-1,0,1} matrices modulo rows permutation (by symmetry this is the same as the number of {-1,0,1} matrices modulo columns permutation), i.e., the number of equivalence classes where two matrices A and B are equivalent if one of them is the result of permuting the rows of the other.
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3
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3, 45, 3654, 1929501, 7355513529, 212787633478239, 47937678641708357304, 85524882506287709213421693, 1224201212028616655577478516173315, 142132497715474639139076246298436794277130
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = C(3^n + n - 1, n) (where C(n, k) denotes the binomial coefficient).
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MATHEMATICA
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Table[Binomial[3^n+n-1, n], {n, 10}] (* Harvey P. Dale, Apr 10 2012 *)
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PROG
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(PARI) { for (n=1, 47, write("b060336.txt", n, " ", binomial(3^n + n - 1, n)); ) } \\ Harry J. Smith, Jul 03 2009
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 25 2001
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EXTENSIONS
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STATUS
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approved
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