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Number of distinct irreducible characteristic polynomials of n X n real robust {0,1}-matrices.
3

%I #8 Nov 07 2013 10:05:03

%S 1,1,6,88,3719

%N Number of distinct irreducible characteristic polynomials of n X n real robust {0,1}-matrices.

%F a(n) = A127182(n) - A127184(n).

%e a(3)=6 because there are 6 different irreducible characteristic polynomials of 3 x 3 binary robust matrices: -1-2y-y^2+y^3,-1-2y-y^2+y^3, -1-y-y^2+y^3, -1+y-2y^2+y^3, -1+2y-3y^2+y^3, 1-y-2y^2+y^3.

%Y Cf. A125587, A125593, A127182, A127184, A127186.

%K nonn

%O 1,3

%A _Artur Jasinski_ and Peter Pein (petsie(AT)dordos.net), Jan 07 2007