OFFSET
1,1
COMMENTS
This is the base-2 equivalent of A009944.
LINKS
Scott R. Shannon, Divisor products for the first 46 terms. These are all the terms up to 100000000.
EXAMPLE
351 is a term as 351 = 101011111_2 = 3 * 117 = 11_2 * 1110101_2, and "101011111" in reverse is "111110101" which equals "11" + "1110101".
See the attached text file for other examples.
MATHEMATICA
Select[Range[2^18], Function[{k, d, m}, AnyTrue[Map[Join @@ IntegerDigits[#, 2] &, Transpose@ {d, k/d}], # == m &]] @@ {#, Divisors[#], Reverse@ IntegerDigits[#, 2]} &] (* Michael De Vlieger, Jul 23 2022 *)
PROG
(Python)
from sympy import divisors
def ok(n):
if not n&1: return False
t = bin(n)[2:][::-1]
return any(t==bin(d)[2:]+bin(n//d)[2:] for d in divisors(n, generator=True))
print([k for k in range(10**6) if ok(k)]) # Michael S. Branicky, Apr 13 2024
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, Jul 21 2022
STATUS
approved