A (49,16,3,6) strongly regular graph does not exist

Graphs;mathematics

A symmetric design with parameters 22-(49,,16,,5)(49,,16,,5)

AbstractA symmetric 2-design with parameters (v, k, λ) = (49, 16, 5) is constructed. Both this design and its residual, a design with parameters (v, b, r, k, λ) = (33, 48, 16, 11, 5), seem to be new. The derived designs do not have repeated blocks. The group of the design is cyclic of order 15. There is no polarity