Agrawal's conjecture on extremal triple arrays

About 10 years old · traced to

Let rr, cc, and d706ccd706_{cc} be parameters of a symmetric 22-design on r+cr+c points, and suppose that r−d706cc>2r-d706_{cc}>2.

Agrawal's conjecture. If there is a symmetric 22-(r+c,r,d706cc)(r+c,r,d706_{cc}) design with r−d706cc>2r-d706_{cc}>2, then there is an (r×c,r+c−1)(r\times c,r+c-1)-triple array.

This conjecture asks whether Agrawal's construction from a symmetric design can always be completed from an unordered triple array to an ordered one under the stated condition. It remains open.

References

Primary source

Alexey Gordeev and Lars-Daniel Öhman, “Resolvable Triple Arrays”, arXiv:2512.08681 (2026).

Additional references

2 papers in this index state this conjecture (2016–2025). The statement above is taken from the most recent of them; the others are arXiv:1609.00152.

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.