Generalised stretched Littlewood–Richardson coefficients

The Littlewood–Richardson (LR) coefficient counts, among many other things, the LR tableaux of a given shape and a given content. We prove that the number of LR tableaux weakly increases if one adds to its shape and content the shape and the content of another LR tableau. We also investigate the behaviour of the number of LR tableaux, if one repeatedly adds to the shape another shape with either fixed or arbitrary content. This is a generalisation of the stretched LR coefficients, where one repeatedly adds the same shape and content to itself.