OFFSET
1,2
COMMENTS
The factors may be equal, but no example for n>2 is known.
EXAMPLE
See A394987.
PROG
(Python)
from sympy.utilities.iterables import multiset_permutations
from sympy import divisors
def A395003(n):
a = 1<<n-1
b = a<<1
k = (n<<1)-1
c = (1<<k+1)-1
for l in range(k, 0, -1):
for s in multiset_permutations('0'*l+'1'*(k+1-l)):
m = c-int(''.join(s), 2)
for d in divisors(m):
if d**2>m:
break
if a<=d<b and a*d<=m<b*d:
return d # Chai Wah Wu, Apr 11 2026
CROSSREFS
KEYWORD
nonn,new
AUTHOR
Hugo Pfoertner, Apr 09 2026
EXTENSIONS
a(24)-a(34) from Chai Wah Wu, Apr 09 2026
STATUS
approved