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a(n) = (n!)^4.
13

%I #20 Oct 04 2018 18:26:07

%S 1,1,16,1296,331776,207360000,268738560000,645241282560000,

%T 2642908293365760000,17340121312772751360000,

%U 173401213127727513600000000,2538767161403058526617600000000,52643875858853821607942553600000000,1503561738404723998944447273369600000000

%N a(n) = (n!)^4.

%C a(n) is also the determinant of the symmetric n X n matrix M defined by M(i,j) = sigma_4(gcd(i,j)) for 1 <= i,j <= n, and n>0, where sigma_4 is A001159. - _Enrique PĂ©rez Herrero_, Aug 13 2011

%H Alois P. Heinz, <a href="/A134375/b134375.txt">Table of n, a(n) for n = 0..100</a>

%F a(n) = det(S(i+4,j), 1 <= i,j <= n), where S(n,k) are Stirling numbers of the second kind. - _Mircea Merca_, Apr 04 2013

%p a:= n-> (n!)^4:

%p seq(a(n), n=0..20); # _Alois P. Heinz_, Aug 15 2013

%t Table[((n)!)^(4), {n, 0, 10}]

%Y Cf. A000142, A001044, A000442, A036740, A010050, A009445, A134366, A134367, A134368, A134369, A134371, A134372, A134373, A134374.

%Y Row n=4 of A225816.

%K nonn

%O 0,3

%A _Artur Jasinski_, Oct 22 2007