%I #23 Dec 21 2013 18:40:07
%S 6,90,2826,179874,22988394,5882561010,3011536790874,3083724807586146,
%T 6315421830476086026,25867919440922274113490,
%U 211909896144041988220786746,3471931327152422147338068920514,113768242349516897374699301112595434,7455915475175021412811907000511105871410
%N Number of acyclic orientations of the bi-iterative graph family G^4_n.
%H Alois P. Heinz, <a href="/A232979/b232979.txt">Table of n, a(n) for n = 0..75</a>
%H T. Kotek, J. A. Makowsky, <a href="http://arxiv.org/abs/1309.4020">Recurrence Relations for Graph Polynomials on Bi-iterative Families of Graphs</a>, arXiv preprint arXiv:1309.4020, 2013
%Y Cf. A232978.
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Dec 07 2013
%E a(7)-a(13) from _Alois P. Heinz_, Dec 21 2013