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A036323
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Composite numbers n such that digits of prime factors of n are either 7 or 8.
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2
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49, 343, 2401, 5509, 6139, 6209, 16807, 38563, 42973, 43463, 55139, 62209, 117649, 269941, 300811, 304241, 385973, 435463, 551509, 552139, 552209, 615139, 615209, 619369, 690199, 698069, 769129, 777899, 786769, 823543, 1889587, 2105677
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OFFSET
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1,1
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COMMENTS
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All terms are a product of at least two terms of A020470. - David A. Corneth, Oct 09 2020
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LINKS
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David A. Corneth, Table of n, a(n) for n = 1..10000
Index entries for sequences related to prime factors
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MATHEMATICA
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Select[Range[25*10^5], CompositeQ[#]&&SubsetQ[{7, 8}, Flatten[ IntegerDigits/@ Transpose[ FactorInteger[#]][[1]]]]&] (* Harvey P. Dale, Jan 19 2015 *)
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CROSSREFS
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Cf. A020470, A036302-A036325.
Sequence in context: A211736 A211747 A211756 * A066429 A269327 A206255
Adjacent sequences: A036320 A036321 A036322 * A036324 A036325 A036326
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KEYWORD
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nonn,easy,base
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AUTHOR
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Patrick De Geest, Dec 15 1998
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STATUS
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approved
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