A089630 - OEIS

%I #13 Jan 30 2023 12:29:11

%S 1,1,4,6,56,1275

%N Size of the smallest n-cluster.

%C 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).

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

%H L. C. Noll and D. I. Bell, <a href="https://doi.org/10.1090/S0025-5718-1989-0970702-0">n-clusters for 1 < n < 7</a>, Math. Comput., 53 (1989), pp. 439-444.

%K nonn,more

%O 1,3

%A _Philippe Deléham_, Jan 03 2004