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A110456
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Largest prime obtained by concatenation of parts of a distinct partition of n. 0 if no such number exist.
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0
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0, 2, 3, 31, 41, 0, 421, 521, 0, 4231, 5231, 0, 7321, 8231, 0, 64231, 74231, 0, 94321, 431021, 0, 754123, 854213, 0, 5431021, 6421013, 0, 8431021, 9431021, 0, 65412103, 75411023, 0, 95421103, 96412103, 0, 643110211, 765324101
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OFFSET
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1,2
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COMMENTS
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Conjecture a(n) = 0 only for n = 1, or n == 0 (mod 3), n is > 3. Subsidiary sequence (hard): Number of primes generated by concatenation of distinct partitions of n.
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LINKS
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EXAMPLE
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Distinct partitions of 10 are 10,(9,1), (8,2), (7,3),...(7,2,1),(6,3,1),(5,3,2),...(4,3,2,1), etc. (4231 is the largest number obtained as a concatenation of (4,2,3,1).
a(10)=4231.
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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