What comes next?

[Gil]

Interesting, but I do not understand where the Matrix in your example comes from.

As mentioned in my 1st post, now with more details and examples, when having
{#1 #2 #3... #n}
with #1=f(0), #2=f(1), #3=f(2),... #n=f(n-1),

then running my program Next_NumberV8 gives 3 outputs:

a) {#1 #2 #3... #n} <again, in stack level 3>;
b) f(x) <the function going through the above points {#1 #2 #3... #n}, in stack level 2>;
c) f(n) <the corresponding number #n+1 following #n, in stack level 1>.