OFFSET
1,1
LINKS
Scott R. Shannon, Divisor product of the first 417 terms. These are all the numbers up to 100000000.
EXAMPLE
6 is a term as 6 = 110_2 = 3 * 2 = 11_2 * 10_2 and "11" + "10" = "1110" contains "110".
2340 is a term as 2340 = 100100100100_2 = 4 * 585 = 100_2 * 1001001001_2 and "100" + "1001001001" contains "100100100100".
See the attached text file for other examples.
MATHEMATICA
q[n_] := AnyTrue[Rest @ Most @ Divisors[n], StringContainsQ[StringJoin @@ IntegerString[{#, n/#}, 2], IntegerString[n, 2]] &]; Select[Range[2, 2500], q] (* Amiram Eldar, Jul 27 2022 *)
PROG
(Python)
from sympy import divisors
def ok(n):
b, divs = bin(n)[2:], divisors(n)[1:-1]
return any(b in bin(d)[2:]+bin(n//d)[2:] for d in divs)
print([k for k in range(1, 2400) if ok(k)]) # Michael S. Branicky, Jul 27 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, Jul 17 2022
STATUS
approved