A171808 Number of 5 X 5 permutation matrices such that the n-th matrix power is the identity matrix and the determinant is +1.

1, 15, 20, 0, 24

Offset

1,2

Comments

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.

Links

Table of n, a(n) for n=1..5.

Example

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

Crossrefs

Cf. A171806, A171809.

Sequence in context: A031112 A219394 A330522 * A134617 A373138 A113529

Adjacent sequences: A171805 A171806 A171807 * A171809 A171810 A171811

Keyword

fini,nonn,full

Author

Artur Jasinski, Dec 18 2009

Status

approved