2,2

a(7) >= 20937. Points (x,y) of the smallest n-cluster for 1 < n < 7 : (0,0), (1,0); (0,0), (3,0), (0,4); (0,0), (3,4), (3,-4), (6,0); (0,0), (16,30), (-16,30), (0,-33), (56,0); (0,0), (546,272), (960,720), (132,720), (546,-1120), (1155,-540).

N. Fardin and B. Langlois, "Ensembles du plan a distances mutuelles rationnelles", Quadrature, 39 (2000), p. 23.

L. C. Noll and D. I. Bell, "n-clusters for 1 < n < 7", Math. Comput., 53 (1989), pp. 439-444.

Sequence in context: A012910 A121661 A131847 this_sequence A058162 A132929 A154668

Adjacent sequences: A089627 A089628 A089629 this_sequence A089631 A089632 A089633

nonn

DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Jan 03 2004