OFFSET
1,1
COMMENTS
After a(93) = 84444, no further terms < 10^18. - Michael S. Branicky, Jun 08 2022
EXAMPLE
871 is a term because d(871) = d(817) = d(178) = d(187) = d(718) = d(781) = 4, where d(n) is the number of divisors of n.
MATHEMATICA
Select[Range[10000], CountDistinct[DivisorSigma[0, FromDigits /@ Permutations[IntegerDigits[#]]]]==1&&CountDistinct[IntegerDigits[#]]>1&]
PROG
(Python)
from sympy import divisor_count
from itertools import permutations
def ok(n):
s, d = str(n), divisor_count(n)
if len(set(s)) == 1: return False
return all(d==divisor_count(int("".join(p))) for p in permutations(s))
print([k for k in range(5500) if ok(k)]) # Michael S. Branicky, Jun 05 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Metin Sariyar, Jun 05 2022
STATUS
approved