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Number of 5 X 5 permutation matrices such that the n-th matrix power is the identity matrix and the determinant is +1.
4

%I #5 Mar 30 2020 15:18:12

%S 1,15,20,0,24

%N Number of 5 X 5 permutation matrices such that the n-th matrix power is the identity matrix and the determinant is +1.

%C Sum of this sequence is equal to the number of permutation matrices with determinant +1 = 5!/2 = 60. For number matrices with determinant = -1 see A171809.

%e a(1)=1 because there is only one matrix whose first power is the identity matrix (this is the identity matrix itself).

%Y Cf. A171806, A171809.

%K fini,nonn,full

%O 1,2

%A _Artur Jasinski_, Dec 18 2009