%I #12 Jan 16 2021 06:40:57
%S 1,5,198,63206,163170556,3410501048325,577465332522075000,
%T 792313244775191409073200,8810729389390415079342840510816
%N Number of 4n X 4n alternating-sign matrices of type UU.
%H G. Kuperberg, <a href="https://arxiv.org/abs/math/0008184">Symmetry classes of alternating-sign matrices under one roof</a>, arXiv:math/0008184 [math.CO], 2000-2001. [A_{UU}(4n)]
%F a(n) = A005156(n)*A059489(n).
%Y Cf. A005156, A059488, A059493.
%K nonn,easy
%O 0,2
%A _Paul Zinn-Justin_, May 16 2007, Jun 04 2007