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A236673
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Exponents of powers of 3 that contain all ten decimal digits.
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5
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39, 45, 47, 48, 53, 57, 60, 61, 62, 63, 64, 65, 67, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 82, 83, 85, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 98, 99, 102, 103, 105, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123
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OFFSET
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1,1
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COMMENTS
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It is conjectured that after a(43), a(n) = n + 63 (i.e., natural numbers beginning with 107).
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LINKS
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EXAMPLE
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3^53 = 19383245667680019896796723, which contains two 1's, two 2's, three 3's, one 4, one 5, five 6's, three 7's, three 8's, four 9's and two 0's, so 53 is in the sequence.
3^57 = 1570042899082081611640534563, which contains four 1's, two 2's, two 3's, three 4's, three 5's, three 6's, one 7, three 8's, two 9's and five 0's.
58 is not in the sequence because there are no 5's in 3^58 = 4710128697246244834921603689.
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MATHEMATICA
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Select[Range[0, 200], Union[IntegerDigits[3^#]] == Range[0, 9] &] (* T. D. Noe, Jan 29 2014 *)
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PROG
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(Python)
def PanDig(x):
..a = '1234567890'
..for n in range(10**3):
....count = 0
....for i in a:
......if str(x**n).count(i) > 0:
........count += 1
......else:
........break
....if count == len(a):
......print(n)
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CROSSREFS
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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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