%I M0080 #16 Jan 26 2019 05:46:50
%S 2,1,1,3,2,1,1,2,4,2,1,2,2,1,2,5,2,2,1,3,2,1,1,3,6,2,2,2,2,2,1,3,2,2,
%T 2,7,3,1,2,4,2,2,1,2,4,1,1,4,6,3,2,3,2,2,2,3,2,2,1,4,2,1,3,8,2,2,1,3,
%U 2,2
%N Number of reduced indefinite binary forms of determinant -n.
%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 362.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H Nachum Dershowitz, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL20/Dershowitz/dersh3.html">Touchard’s Drunkard</a>, Journal of Integer Sequences, Vol. 20 (2017), #17.1.5.
%Y Cf. A006371, A006374.
%K nonn,hard
%O 1,1
%A _N. J. A. Sloane_.
%E Corrected Apr 15 1995