Number of alternating sign 2n X 2n matrices invariant under flips in both diagonals.

A057629

Number of alternating sign 2n X 2n matrices invariant under flips in both diagonals.

Terms

    a(0) =2a(1) =8a(2) =52a(3) =568a(4) =10436a(5) =323144a(6) =16866856a(7) =1484714416a(8) =220426128584

External references