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A094223
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Number of binary n X n matrices with all rows (columns) distinct, up to permutation of columns (rows).
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0
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1, 2, 7, 68, 2251, 247016, 89254228, 108168781424, 451141297789858, 6625037125817801312, 348562672319990399962384, 66545827618461283102105245248, 46543235997095840080425299916917968
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| G. Kilibarda and V. Jovovic, "Enumeration of some classes of T_0-hypergraphs", in preparation, 2004.
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FORMULA
| a(n) = Sum((-1)^(n-k)*Stirling1(n, k)*binomial(2^k, n), k=0..n) = Sum(Stirling1(n, k)*binomial(2^k+n-1, n), k=0..n).
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MATHEMATICA
| a[n_] := Sum[(-1)^(n - k)*StirlingS1[n, k]*Binomial[2^k, n], {k, 0, n}]; (* or *) a[n_] := Sum[ StirlingS1[n, k]*Binomial[2^k + n - 1, n], {k, 0, n}]; Table[ a[n], {n, 0, 12}] (from Robert G. Wilson v May 29 2004)
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CROSSREFS
| Main diagonal of A059584 and A059587, A060690, A088309.
Sequence in context: A133237 A099660 A173226 * A113866 A165978 A106917
Adjacent sequences: A094220 A094221 A094222 * A094224 A094225 A094226
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KEYWORD
| easy,nonn
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AUTHOR
| Goran Kilibarda, Vladeta Jovovic (vladeta(AT)eunet.rs), May 28 2004
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), May 29 2004
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