OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..13
EXAMPLE
120 = 10*12 belongs to this sequence and 360 = 18*20 is the smallest such multiple of 120.
PROG
(Python)
from itertools import islice
from sympy import sqrt_mod_iter
def A068859_gen(): # generator of terms
a = 3
while True:
yield a
b = a+1
for d in sqrt_mod_iter(1, a):
if d==1 or d**2-1 == a:
d += a
if d < b:
b = d
a = b**2-1
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 12 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 23 2002
Edited by Don Reble, Sep 12 2003
STATUS
approved