e/Pascal's simplex

Information
has gloss	eng: In mathematics, Pascals simplex is a version of Pascals triangle of more than three dimensions. As the triangle and tetrahedron are used to show the binomial and trinomial coefficients respectively, so an n-dimensional simplex is used to show the coefficients of an expression with n terms. The entries in Pascal's simplex are the multinomial coefficients:
lexicalization	eng: Pascal's simplex
instance of	c/Triangles of numbers