Problem

Source: 2020 IGMO Shortlist (N3) https://artofproblemsolving.com/community/c594864h2364137p19272184

Tags: number theory, system of equations, diophantine, Diophantine Equations



Find $a, b, c, d \in N$ such that: $$a + 2^b + 3^c = 3d! + 1$$and exist $p, q$ prime such that : $$a = (p + 1)(2p + 1) = (q + 1)(q - 1)^2$$