Number of (n+1)X4 0..1 arrays with rows and columns of permanents of all 2X2 subblocks lexicographically nondecreasing, and all 2X2 permanents nonzero.

A204735

Number of (n+1)X4 0..1 arrays with rows and columns of permanents of all 2X2 subblocks lexicographically nondecreasing, and all 2X2 permanents nonzero.

Terms

    a(0) =31a(1) =115a(2) =409a(3) =1389a(4) =4658a(5) =15327a(6) =50177a(7) =163232a(8) =530016a(9) =1717764a(10) =5563837a(11) =18012221a(12) =58302070a(13) =188688609a(14) =610642633a(15) =1976129278a(16) =6394969908a(17) =20694674546a(18) =66969565365a(19) =216718343291a(20) =701315733834

External references