Number of n X n symmetric 0-1 matrices where rows are sorted lexicographically and row sums are nondecreasing.

A351158

Number of n X n symmetric 0-1 matrices where rows are sorted lexicographically and row sums are nondecreasing.

Terms

    a(0) =2a(1) =5a(2) =15a(3) =56a(4) =275a(5) =1897a(6) =18948

External references