%I #39 May 06 2015 05:02:48
%S 2,20,648,45472,5644880,1099056000,310007943616,119777421416192
%N Number of hopping sequences in four-colored rooted trees with n nodes, starting and ending with the same "initial state" from all of the (two-colored) rooted trees in A198760. See comments.
%C Compared to A225823, both node colors of the initial states are mobile on the tree (Hubbard model). - _Eva Kalinowski_, Jul 30 2013
%D G. Gruber, Entwicklung einer graphbasierten Methode zur Analyse von Hüpfsequenzen auf Butcherbäumen und deren Implementierung in Haskell, Diploma thesis, Marburg, 2011
%D M. Paech, E. Kalinowski, W. Apel, G. Gruber, R. Loogen, and E. Jeckelmann, Ground-state energy and beyond: High-accuracy results for the Hubbard model on the Bethe lattice in the strong-coupling limit, DPG Spring Meeting, Berlin, TT 45.91 (2012)
%H Eva Kalinowski and Władysław Gluza, <a href="http://arxiv.org/abs/1106.4938">Evaluation of High Order Terms for the Hubbard Model in the Strong-Coupling Limit</a> arXiv:1106.4938, 2011 (Physical Review B, January 2012)
%H Martin Paech, <a href="http://edok01.tib.uni-hannover.de/edoks/e01dh15/821459422.pdf">Numerische und algebraisch-graphentheoretische Algorithmen für korrelierte Quantensysteme</a>, Dissertation, Hannover, 2015 (in German with an abstract in English).
%Y Cf. A000081, A038055, A136793, A198760, A225823.
%K nonn,more
%O 2,1
%A _N. J. A. Sloane_, Oct 29 2011
%E Terms a(8) and a(9) added by _Martin Paech_, Apr 16 2012