random

hey /prog/.

is there a random number generator algorithm/library that supports something like this: use this seed, give me next nth random number? obviously it shouldn't iterate n times. I don't care if it is not that random.

there is probably something very simple for this but I can't get my head around it.

>>1
What for do you need that?

Any old linear congruential generator can do that, obviously: represent one step as a matrix over the modulo field, rise the matrix to n-th power in log(n) steps. But LGCs suck.

The state of the art in PRNG is Mersenne Twister, it can't be fast-forwarded like that apparently, but given its period you can just start with consecutive natural numbers as seeds and be sure to get non-intersecting subsequences of reasonable length. If you want to get some deterministic non-intersecting subsequences. What do you want, OP?