Number of n X n nonnegative integer arrays with each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it).

A202544

Number of n X n nonnegative integer arrays with each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it).

Terms

    a(0) =1a(1) =2a(2) =18a(3) =1094a(4) =658492a(5) =5534917394

External references