A construction of some symmetric designs with parameters (196,91,42)
Dean Crnković · International Mathematical Forum · 2007
Let q be a prime power, q ≡ 1 (mod 4), and let p = q+12. We construct an orbit structure for the parameters (4p2, 2p2−p, p2−p) and the orbit size distribution with q + 1 fixed points and 2q orbits of size p. Further, we describe a construction of eight symmetric designs with parameters (196,91,42) admitting an automorphism group isomorphic to Frob7·3 × Z6.