Number of n X n symmetric positive semi-definite matrices with 2's on the main diagonal and 1's and 0's elsewhere.

A085658

Number of n X n symmetric positive semi-definite matrices with 2's on the main diagonal and 1's and 0's elsewhere.

Terms

    a(0) =1a(1) =2a(2) =8a(3) =64a(4) =924a(5) =21737a(6) =749684a(7) =33568376

External references