Is it true that if a Steiner triple system STS(v) exists, then there are systems STS(6v+1) and STS(6v+3) containing an STS(v) as a subsystem?

It is well known that for every nonnegative n, there exist Steiner triple systems STS(6n+1) and STS(6n+3). I see similarities between this statement and the one that I included in my question, but...

13 January 2020 5,876 1 View