Number walls are a tool for analyzing integer sequences. The sequence is
input into the top row, and the other rows of numbers are calculated
according to the cross rule (by solving for D):
There are other more elaborate rules for cases where zeros make the cross
rule useless (when C is 0). For more details, see this
UI note: For numbers that don't fit, I just write "big", but you can hover
over the cell to see the actual value.
Using the number wall, we can deduce a recurrence relation for the
The predicted next values are:
The number wall doesn't converge to zeros. Either there is no simple
recurrence relation, or we haven't evaluated enough of the wall.
and after aaaaaaall
you're my number waaaaaaall