Algebraic independence of the numbers ∏ K = 0 ∞ ( 1 - p - 2 K ) with p prime Kenneth K. Kubota Séminaire Delange-Pisot-Poitou. Théorie des nombres
The algebraic independence of Weierstrass functions and some related numbers W. Brownawell; K. Kubota — 1977 Acta Arithmetica