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A284788
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Even numbers that cannot be represented in at least two ways as the sum of two odd composites.
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2
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2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 32, 34, 38, 40, 44, 46, 52, 56, 62, 68
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internal format)
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OFFSET
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1,1
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COMMENTS
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If n is even and n > 68, then n can be written as at least two distinct sums of two composite odd integers.
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REFERENCES
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D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, 1997, page 111.
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LINKS
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EXAMPLE
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34 is in the sequence because 34 = 9 + 25 but cannot be represented in a second way as the sum of two odd composites with 9, 15, 21, 25, 27, 33.
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MATHEMATICA
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oddco = Select[Range[9, 100, 2], ! PrimeQ[#] &]; Select[Range[2, 100, 2], Length@ Quiet@ IntegerPartitions[#, {2}, oddco, 2] < 2 &] (* Giovanni Resta, Apr 03 2017 *)
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CROSSREFS
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KEYWORD
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fini,full,nonn
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AUTHOR
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STATUS
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approved
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