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A097476 a(n)=prod(i=0,n-1,((2i)!)^2). 1
1, 4, 2304, 1194393600, 1941728542064640000, 25569049282962188245401600000000, 5866627428836325123819714259080708096000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = determinant of n X n matrix m(i,j)=E(2i+2j), 0<=i,j<=n-1, where E(2k) is the (2k)-th signless Euler number in 1/cos(z)=sum(k>=0,E(2k)*z^(2k)/(2k)!)

REFERENCES

C. Krattenthaler, Advanced Determinant Calculus, p. 46

LINKS

Table of n, a(n) for n=1..7.

C. Krattenthaler, Advanced Determinant Calculus.

PROG

(PARI) a(n)=prod(i=0, n-1, ((2*i)!)^2)

CROSSREFS

Sequence in context: A192889 A062407 A212799 * A047676 A280790 A079187

Adjacent sequences:  A097473 A097474 A097475 * A097477 A097478 A097479

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Sep 18 2004

STATUS

approved

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Last modified October 21 08:00 EDT 2018. Contains 316405 sequences. (Running on oeis4.)