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A201055
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Composite numbers whose product of digits is 6.
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1
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6, 16, 32, 116, 123, 132, 161, 213, 231, 312, 321, 611, 1116, 1132, 1161, 1312, 1611, 3112, 3211, 6111, 11116, 11123, 11132, 11231, 11312, 11611, 12131, 12311, 13112, 13211, 21113, 21131, 21311, 23111, 31112, 31211, 32111, 61111, 111116, 111123, 111132, 111161
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Number 123 is in sequence because 1*2*3 = 6.
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PROG
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(Python)
from sympy import prod, isprime
from sympy.utilities.iterables import multiset_permutations
def agen(maxdigits):
for digs in range(1, maxdigits+1):
for mp in multiset_permutations("1"*(digs-1) + "236", digs):
if prod(map(int, mp)) == 6:
t = int("".join(mp))
if not isprime(t): yield t
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CROSSREFS
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Cf. A199988 (numbers whose product of digits is 6).
Complement of A107692 (primes whose product of digits is 6) with respect to A199988.
Subsequence of A201020 (composite numbers whose multiplicative digital root is 6).
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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