In this paper we
demonstrate that the equation of the title has exactly three solutions in
positive integers, namely: 1 ⋅ 2 ⋅ 3 ⋅ 4 = 2 ⋅ 3 ⋅ 4,2 ⋅ 3 ⋅ 4 ⋅ 5 = 4 ⋅ 5 ⋅ 6 and
19 ⋅ 20 ⋅ 21 ⋅ 22 = 55 ⋅ 56 ⋅ 57. The method of proof is to reduce the equation to the
form y2= x3− x + 1.