OFFSET
1,1
COMMENTS
No number is obtainable by permuting the digits of other members - only one with ascending order of digits is included.
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
EXAMPLE
1339 belongs to this sequence but 1933 does not.
MATHEMATICA
a = {}; b = 3; Do[c = Apply[ Times, IntegerDigits[n]]/b^Floor[ Log[10, n] + 1]; If[c == 1 && Position[a, FromDigits[ Sort[ IntegerDigits[n]]]] == {}, Print[n]; a = Append[a, n]], {n, 1, 10^8}]
PROG
(Python)
from math import prod
from sympy.utilities.iterables import multiset_combinations
def aupton(terms):
n, digits, alst, powsexps3 = 0, 1, [], [(1, 0), (3, 1), (9, 2)]
while n < terms:
target = 3**digits
mcstr = "".join(str(d)*(digits//max(1, r)) for d, r in powsexps3)
for mc in multiset_combinations(mcstr, digits):
if prod(map(int, mc)) == target:
n += 1
alst.append(int("".join(mc)))
if n == terms: break
else: digits += 1
return alst
print(aupton(31)) # Michael S. Branicky, Apr 28 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Mar 30 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Apr 01 2002
Name edited and a(30) and beyond from Michael S. Branicky, Apr 28 2021
STATUS
approved