What is the actual RNG that my compiler uses for the rand() function?

[wtf]

I have not been able to find the documentation for it. It always begins with this sequence when I do not seed it with time first.

41
18467
6334
26500
19169
15724
11478
29358
26962
24464

[helios]

I don't know if it's defined in the standard, but most compilers use a linear congruential generator for rand().

[wtf]

but which LCG would yield the above sequence?

[helios]

The Wikipedia article on LCGs has the generators for the most popular compilers. You could try each formula to see which one fits.
I don't see what could possibly be the use of doing this, though.

[Duthomhas]

Moreover, the RNG that comes in the standard library is underpowered and not very balanced.
If you really want something nice, google around "mersenne twister".