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A051680
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Number of n X n invertible matrices A over GF(3) such that A-I is invertible.
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1
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1, 27, 6291, 13589289, 266377183929, 47123189360124723, 75095231825148137471259, 1077370264330489309698453375441, 139124702920688202983704723564457669361
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OFFSET
| 1,2
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FORMULA
| a(n) = 3^binomial(n,2)*b(n), with b(0)=1, b(n)=(3^n-1)*b(n-1)+(-1)^(n). - Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 20 2006
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MATHEMATICA
| a[n_] := a[n] = 3^(n-1)*((3^n-1)*a[n-1] + (-1)^n*3^((n-3)*n/2+1)); a[1] = 1; Table[a[n], {n, 1, 9}] (* From Jean-François Alcover, Jan 12 2012, after formula *)
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CROSSREFS
| Cf. A002820.
Sequence in context: A046367 A059795 A123395 * A013828 A001321 A111415
Adjacent sequences: A051677 A051678 A051679 * A051681 A051682 A051683
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KEYWORD
| nonn,nice
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 17 2000
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