Lower bound of t-blocking sets in pg (2, q)‎ and existence of minimal blocking sets of size 16 and 17 in pg (2, 9)‎

الملخص EN

In this paper we introduce the projective plane PG(2, q), q square the lower bound of 5 – blocking set when q > 25 and q = 16.

Then we improved the lower bound of 5 – blocking set when q 10.

Also we find the lower bound of a 6 -blocking set when q > 36 and q = 16.

Specially in projective plane PG(2, 9), we show that the minimal blocking set of size 16 with a 6 – secant and the minimal blocking set of size 16 of Rédei-type are exists and we classify the minimal blocking sets of size 17.