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A048616 Denominator of mass (Sum 1/|Aut(H)|) of Hadamard matrices of order 4n. 5
192, 21504, 190080, 573440, 218880, 40480, 2106, 53329920 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..8.

V. Alvarez, J. A. Armario, M. D. Frau and F. Gudiel, The maximal determinant of cocyclic (-1, 1)-matrices over D_{2t}, Linear Algebra and its Applications, 2011.

Index entries for sequences related to Hadamard matrices

EXAMPLE

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

CROSSREFS

Cf. A048615, A007299, A036297.

Sequence in context: A200209 A205760 A035833 * A206707 A199007 A199006

Adjacent sequences:  A048613 A048614 A048615 * A048617 A048618 A048619

KEYWORD

frac,nonn,hard,nice

AUTHOR

N. J. A. Sloane, E. M. Rains

EXTENSIONS

a(8) from Brendan McKay, Feb 11 2012

STATUS

approved

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Last modified April 5 20:24 EDT 2020. Contains 333260 sequences. (Running on oeis4.)