A059488 Expansion of generating function A_{UU}^(2)(4n;2,1,1).

1, 6, 140, 12936, 4756752, 6974908512, 40825196325056, 954410297723625600, 89149543741372647686400, 33280303224443643993143232000, 49660896290963321355372907102080000, 296248087478941460167300263349693113600000, 7065635944743752671502919147104799866118720000000

Offset: 0

Author

N. J. A. Sloane, Feb 04 2001

Keywords

• nonn
• easy

Links

• G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv math.CO/0008184 [Th. 5]

Programs

Maple

A059488 := proc(n) local i, j, t1; t1 := 2^(n^2 + 2*n); for i to 2*n + 1 do for j to 2*n + 1 do if i mod 2 <> 0 and j mod 2 = 0 then t1 := t1*(2*j - 2*i + 1)/(2*j - 2*i) end if end do end do; t1 end proc;