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A085274
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(n!/n#) + 1 is a semiprime, where n# = primorial numbers A034386.
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0
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6, 10, 21, 22, 24, 25, 27, 30, 39, 48, 52, 57, 65, 87, 94, 110, 114, 124
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OFFSET
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0,1
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COMMENTS
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n!/n# is called n compositorial. The actual sequence is (6,7),(10,11),21,(22,23),24,25,27,(30,31),39,48, (52,53),57,65,... where the values in parenthesis yield the same semiprime.
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LINKS
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Table of n, a(n) for n=0..17.
Hisanori Mishima, Compositorial + 1 (n = 4 to 150).
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EXAMPLE
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25!/25# + 1 is a product of two primes: 69528040243200001 = 2594807 * 26795071943.
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CROSSREFS
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Cf. A001358, A049420, A049614.
Sequence in context: A153369 A107981 A065758 * A175648 A178661 A190273
Adjacent sequences: A085271 A085272 A085273 * A085275 A085276 A085277
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KEYWORD
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nonn
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AUTHOR
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Jason Earls (zevi_35711(AT)yahoo.com), Aug 12 2003
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EXTENSIONS
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More terms from Robert G. Wilson v, Aug 15 2003
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STATUS
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approved
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