We prove that under very mild conditions for any interpolation formula f(x)=∑λ∈Λf(λ)aλ(x)+∑μ∈Mf^(μ)bμ(x) we have a lower bound for the counting functions nΛ(R1)+nM(R2)≥4R1R2−Clog2(4R1R2) which very closely matches recent interpolation formulas of Radchenko and Viazovska and of Bondarenko, Radchenko and Seip
