We search for three distinct polynomials with integer coefficients such that the product of any two members of the set added with their sum and increased by a non-zero integer (or polynomial with integer coefficients) is a perfect square.
The Bulletin of Society for Mathematical Services and Standards (Volume 10)
M.A. Gopalan et al., "DIO 3 - Tuples for Special Numbers - I", The Bulletin of Society for Mathematical Services and Standards, Vol. 10, pp. 1-6, 2014