A346674 Nonnegative numbers k such that MD5(k interpreted as a string) contains only decimal digits.

1518375, 6637317, 16781059, 20274157, 20680348, 22080638, 24026537, 25394302, 26059015, 28926467, 40459791, 42057668, 42390227, 42943634, 43983547, 47788382, 49974597, 51201829, 59344568, 63236613, 63341298, 70557689, 74946923, 76642382, 77213479, 77641296

Offset

1,1

Comments

See A234849 for more information about MD5.

This sequence is probably infinite, because MD5 returns a fixed-length output, but we don't know if outputs containing only decimal digits appear infinitely many times. Even if this is the case, it would not be enough, as we would not know if this holds when we consider the input as a number (interpreted as a string).

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Wikipedia, MD5

Example

a(1) = 1518375, because 1518375 is the smallest k >= 0 such that MD5(k) contains only decimal digits: MD5("1518375") = "93240121540327474319550261818423".

Mathematica

Monitor[Do[If[!StringContainsQ[Hash[ToString@k, "MD5", "HexString"], Alphabet[]], Print@k], {k, 10^9}], k] (* Giorgos Kalogeropoulos, Jul 28 2021 *)

Prog

(Python)
from hashlib import md5
i=0
while True:
    m = md5()
    m.update(str(i).encode('utf-8'))
    result = m.hexdigest()
    if result.isdecimal():
        print(i)
    i+=1

Crossrefs

Cf. A234849.

Sequence in context: A254166 A254455 A177004 * A236154 A126252 A268305

Adjacent sequences: A346671 A346672 A346673 * A346675 A346676 A346677

Keyword

easy,nonn,base

Author

Eder Vanzei, Jul 28 2021

Status

approved