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A284309 Number of singular vector tuples for a general n-dimensional {n}^n tensor. 1

%I #8 Aug 06 2018 10:59:52

%S 1,2,37,51264,14346274601,1435747717722810960,

%T 79118094349714452632485774477,

%U 3409699209687052091502059492845005192560640,154730604283618051465998344012575355916858352712971348277665,9576184829775011641104888042379740657096306109466956243538100418643876547244800

%N Number of singular vector tuples for a general n-dimensional {n}^n tensor.

%H Shalosh B. Ekhad and Doron Zeilberger, <a href="http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/svt.html">On the Number of Singular Vector Tuples of Hyper-Cubical Tensors</a>, 2016; also arXiv preprint arXiv:1605.00172, 2016.

%H Shmuel Friedland and Giorgio Ottaviani, <a href="http://dx.doi.org/10.1007/s10208-014-9194-z">The number of singular vector tuples and uniqueness of best rank-one approximation of tensors</a>, Found. Comput. Math. 14 (2014), no. 6, 1209-1242.

%H Bernd Sturmfels, <a href="http://www.ams.org/publications/journals/notices/201606/rnoti-p604.pdf">Tensors and Their Eigenvalues</a>, Notices AMS, 63 (No. 6, 2016), 606-606.

%t a[1] = 1;

%t a[n_] := Module[{Z, z, P},

%t Z[i_] := Sum[z[k], {k, 1, n}] - z[i];

%t P = Product[(Z[i]^n - z[i]^n)/(Z[i] - z[i]), {i, 1, n}] // Cancel;

%t SeriesCoefficient[P, Sequence @@ Table[{z[i], 0, n-1}, {i, 1, n}]]

%t ];

%t Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 1, 5}] (* _Jean-François Alcover_, Aug 06 2018 *)

%Y Main diagonal of A284308.

%K nonn

%O 1,2

%A _Alois P. Heinz_, Mar 24 2017

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)