A107445 Number of 4n X 4n alternating-sign matrices of type UU.

1, 5, 198, 63206, 163170556, 3410501048325, 577465332522075000, 792313244775191409073200, 8810729389390415079342840510816

Offset: 0

Author

Paul Zinn-Justin, May 16 2007, Jun 04 2007

Keywords

• nonn
• easy

Links

• G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv:math/0008184 [math.CO], 2000-2001. [A_{UU}(4n)]

Crossrefs

Cf. A005156, A059488, A059493.

Formula

a(n) = A005156(n)*A059489(n).