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A048616 Denominator of mass (Sum 1/|Aut(H)|) of Hadamard matrices of order 4n. 5

%I #17 Dec 17 2016 10:28:43

%S 192,21504,190080,573440,218880,40480,2106,53329920

%N Denominator of mass (Sum 1/|Aut(H)|) of Hadamard matrices of order 4n.

%H V. Alvarez, J. A. Armario, M. D. Frau and F. Gudiel, <a href="http://dx.doi.org/10.1016/j.laa.2011.05.018">The maximal determinant of cocyclic (-1, 1)-matrices over D_{2t}</a>, Linear Algebra and its Applications, 2011.

%H <a href="/index/Ha#Hadamard">Index entries for sequences related to Hadamard matrices</a>

%e 1/192, 1/21504, 1/190080, 27/573440, 127/218880, 34603/40480, 278617/2106, 264156210586399/53329920, ...

%Y Cf. A048615, A007299, A036297.

%K frac,nonn,hard,nice

%O 1,1

%A _N. J. A. Sloane_, E. M. Rains

%E a(8) from _Brendan McKay_, Feb 11 2012

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)