Naslov
Classification of symmetric block design for (71, 21, 6) with nonabelian group of order 21

Autori
Ademaj, Eshref ; Essert, Mario

Izvornik
Mathematical communications (1331-0623) 9 (2004), 1; 45-49

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
block design; automorphism group; collineation

Sažetak
Thwe existence of symmetric block design for (71, 21, 6) was doubtful until the discovery of Z. Janko and T. van Trung of the so-called "non-human" design. In this paper we have classified designs with the above parameters, admitting all possible actions of the nonabelian group of order 21 on them, which is indeed the full automorphism group of the Janko-van Trung design. We have proved that there is only one symmetric block design for (71, 21, 6), together with its dual, with the Frobenius group of order 21, namely the Janko-van Trung design.

Izvorni jezik
Engleski

Znanstvena područja
Računarstvo

POVEZANOST RADA