The geometric meaning of a function P"d" is: P"d"(1) = 1 for all "d". Construct a "d"-dimensional triangle (a 3-dimensional triangle is a tetrahedron) by placing additional dots below an initial dot, corresponding to P"d"(1) = 1. Place these dots in a manner analogous to the placement of numbers in Pascal's triangle. To find P"d"("x"), have a total of "x" dots composing the target shape. P"d"("x") then equals the total number of dots in the shape. A 0-dimensional triangle is a point and a 1-dimensional triangle is simply a line, and therefore P0("x") = "1" and P1("x") = "x", which is the sequence of natural numbers. The number of dots in each layer corresponds to P"d" − 1("x").