EN
Let 1 ≤ p < ∞, $𝒳 = (Xₙ)_{n∈ℕ}$ be a sequence of Banach spaces and $l_{p}(𝒳)$ the coresponding vector valued sequence space. Let $𝒳 = (Xₙ)_{n∈ℕ}$, $𝓨 = (Yₙ)_{n∈ℕ}$ be two sequences of Banach spaces, $𝒱 = (Vₙ)_{n∈ℕ}$, Vₙ: Xₙ → Yₙ, a sequence of bounded linear operators and 1 ≤ p,q < ∞. We define the multiplication operator $M_{𝒱}: l_{p}(𝒳) → l_{q}(𝓨)$ by $M_{𝒱}((xₙ)_{n∈ℕ}) : = (Vₙ(xₙ))_{n∈ℕ}$. We give necessary and sufficient conditions for $M_{𝒱}$ to be 2-summing when (p,q) is one of the couples (1,2), (2,1), (2,2), (1,1), (p,1), (p,2), (2,p), (1,p), (p,q); in the last case 1 < p < 2, 1 < q < ∞.