Most of people knows the following problem, What is the next term ? What expression would give us the general term ? It would be nice to have a formula to generate all the terms in the sequence. how do we find the formula? here is the way to become a 'genius' at MENSA tests.
The Riordan group is a group of infinite lower triangular matrices that are defined by two generating functions, g and f. The kth column of the matrix has the generating function gf k. In the Double Riordan group there are two generating function f 1 and f 2 such that the columns, starting at the left, have generating functions using f 1 and f 2… (More)