$$\infty $$-Operads via symmetric sequences

Abstract We construct a generalization of the Day convolution tensor product presheaves that works for certain double $$\infty $$ ∞ -categories. Using this construction, we obtain an -categorical version well-known description (one-object) operads as associative algebras in symmetric sequences; more generally, show (enriched) -operads with varying spaces objects can be described -category collections.