# Is there a common symbol for concatenating two (finite) sequences?

Say we have two finite sequences $X = (x_0,...,x_n)$ and $Y = (y_0,...,y_n)$.
Is there a more or less common notation for the concatenation of these sequences, like $\sum (X,Y) = (x_0,...,x_n,y_0,...,y_n)$?

The comments suggest the following notations for the concatenation of $$XX$$ and $$YY$$:
• $$X⌢YX^\frown Y$$ (given by X^\frown Y);
• $$XYXY$$ (given by XY);
• $$X⋅YX \cdot Y$$ (given by X \cdot Y);
• $$X‖X \mathbin\Vert Y$$ (given by X \mathbin\Vert Y);