In mathematics, Somos' quadratic recurrence constant, named after Michael Somos, is the number This can be easily re-written into the far more quickly converging product representation which can then be compactly represented in infinite product form by: The constant σ arises when studying the asymptotic behaviour of the sequence with first few terms 1, 1, 2, 12, 576, 1658880, ... (sequence A052129