Well the idea behind using Fibonacci numbers in delay is that (first google them to understand a bit more of them) since they are a natural ocurring sequence and form from one number to the other when using 2 numbers (2 delay times) that are one after the other on the sequence you get delay times that interact with one another allmost like reverb and they dont mess each other up like if you use two random delay times. Steve Vai uses them I think. But basicly uf you want to use 2 delay times to open up the sound by having them blend nicely the you can use 2 of this number un sequence:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597,...
BTW to have a more reverb type of delay you use longer numbers, I'm using now 610 and 987 but to have them blend better the one with the higher number I have it with a but less feedback so the finish their repeats at around the same time and also its level is a bit lower than the first because when the first repet of the 987 delay comes its a bit before the second repet of the 610 delay and if I dont put that one with a bit less volume then it will stick out instead of blending together.