This genertor is posted for informational purposes only. It has some unnice properties which make it unsuitable for some purposes.

```

/*
ULTRA
This is a version of ULTRA,  a generator that was posted on the net
a few years ago.  It combines the lagged Fibonacci generator
x(n)=x(n-99)*x(n-33)  mod 2^32, x's odd
with the multiply-with-carry generator
y(n)=30903*y(n-1)+carry mod 2^16,
returning x(n)+y(n) mod 2^32.
By itself, the lagged Fibonacci generator using multiplication
passes all tests except those dependent on the last bit, since
the output integers are always odd.  Adding the MWC sequence
provides a proper mix of trailing bits. The resulting combination
in ULTRA seems to pass all tests and has a very long period.
That period is  3*2^96*(30903*2^15-1),  about 2^127.5

*/

/* Initialized data */
#define ulong unsigned long

static int ultra_r = 17;
static int ultra_s = 5;
static ulong ultra_mwcs = 15;
static ulong ultra_juni;
static ulong ultra_ju[17] = {
364541503,3961085081,3414663911,2762688119,2540080365,
3733059389, 367198775, 362576243,1637345271,2107418755,
2273955929, 352233113, 301124023, 410255677,4217379025,
1341101751,3534999107
};

void seed_rand_ultra(ulong seed) {
ulong i, j, k, l, js;
int ii;

i = seed|1;
j = seed|2;
k = seed|4;
l = seed|8;

ultra_mwcs = i + j + k + l;

for (ii = 0; ii < 17; ++ii) {
i = (i & 65535) * 18273 + (i >> 16);
j = (j & 65535) * 23163 + (j >> 16);
k = (k & 65535) * 24984 + (k >> 16);
l = (l & 65535) * 28854 + (l >> 16);
js = (i << 16) + (j & 65535) + (k << 16) + (l & 65535);
js |= 1;
ultra_ju[ii] = js;
}
ultra_r = 17;
ultra_s = 5;
}

ulong rand_ultra(void)
{
ultra_juni = ultra_ju[ultra_r] * ultra_ju[ultra_s];
ultra_ju[ultra_r] = ultra_juni;
if (ultra_r == 0) {
ultra_r = 17;
}
--ultra_r;
if (ultra_s == 0) {
ultra_s = 17;
}
--ultra_s;
ultra_mwcs = (ultra_mwcs & 65535) * 30903 + (ultra_mwcs >> 16);

return ultra_juni + ultra_mwcs;
}

```