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A333788
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Semiprimes whose both factors are Fermat primes.
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6
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9, 15, 25, 51, 85, 289, 771, 1285, 4369, 66049, 196611, 327685, 1114129, 16843009, 4295098369
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OFFSET
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1,1
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COMMENTS
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Product of two, not necessarily distinct Fermat primes.
For the finiteness or non-finiteness of this sequence, see A019434.
Most terms are binary palindromes (in A006995), except among the fifteen known terms, these squares > 9 are not: 25, 289, 66049, 4295098369.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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