hello, im messing around with recursion and attempting to do things without loops in apl. im currently tackling the power operator, trying to use it to give me the nth element of a sequence, provided the nth element is beneath a certain limit.
i have the mathematical sequence: {2, 10, 50, 250,...}
and i wish to get the last element of it before the elements go over 10000.
in this example, the value i would be looking for is 6250, as the next element after that is 31250, which is more than 10000.

i thought of the mathematical function analysis way of solving it, as well as thinking of a possibility of solving the problem by computing twice, but didnt want to do those. cool solutions, thanks!

about your last solution: what do the ⍺←⊢ in the dfns of p do? i havent played much around with combining tacit and dfn forms, as it might look like here.
i assume p works so that it takes a left function and left argument and maybe "binds" it to the function like ⍣ composes its left argument with its left function. p also takes a right function and argument, where the right function is the con…