Code to generate a map between pairs of pre-2011 SSNs.

t.py

import random
import sys

L_AREA = 649
H_AREA_LOW = 700
H_AREA = 29

A_SIZE = L_AREA + H_AREA
G_SIZE = 99
S_SIZE = 9999
T_SIZE = A_SIZE * G_SIZE * S_SIZE

def rand_area():
    cat = random.random()
    if cat < (float(L_AREA) / A_SIZE):
        return random.randint(1, L_AREA)
    else:
        return random.randint(H_AREA_LOW, H_AREA_LOW + H_AREA)

def rand_ssn():
    area = rand_area()
    group = random.randint(1, G_SIZE)
    serial = random.randint(1, S_SIZE)
    return (area, group, serial)

def rand_map(size):
    for _ in xrange(size):
        yield rand_ssn(), rand_ssn()

first_ssn = (1, 1, 1)
def inc_ssn((area, group, serial)):
    serial = (serial + 1) % (S_SIZE + 1)
    if serial == 0:
        serial += 1
        group = (group + 1) % (G_SIZE + 1)
        if group == 0:
            group += 1
            area = (area + 1)
            if H_AREA_LOW > area > L_AREA:
                area = H_AREA_LOW
            elif area == (H_AREA_LOW + H_AREA + 1): 
                raise StopIteration()
    return (area, group, serial)

def iter_ssn(from_=first_ssn):
    yield from_ 
    ssn = from_ 
    while True:
        ssn = inc_ssn(ssn)
        yield ssn

def rand_unique_map():
    for ssn in iter_ssn():
        yield ssn, rand_ssn()

def does_rand_collide(map):
    for i, (a, b) in enumerate(map):
        sys.stdout.write("Testing: %s\r" % i)
        sys.stdout.flush()
        if a == b: return True
    return False