A098854 - OEIS

%I #12 Mar 04 2020 05:55:02

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,2,6,40,303

%N Number of triangle-free self-polar configurations of type (n_3).

%H A. Betten, G. Brinkmann and T. Pisanski, <a href="https://doi.org/10.1016/S0166-218X(99)00143-2">Counting symmetric configurations v_3</a>, Discrete Appl. Math., 99 (2000), 331-338.

%Y Cf. A001403, A098702, A023994.

%K nonn,hard,more

%O 1,18

%A _N. J. A. Sloane_, Nov 05 2004