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A090907
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Ratio of products of successive rows of the irregular triangle defined in A090905.
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4
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OFFSET
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1,1
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COMMENTS
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Conjecture: For n > 4 the last term of the n-th group is 2p where p is the largest prime in the (n-1)th group. And these are the Bertrand primes.
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LINKS
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EXAMPLE
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a(1)=(2!/1!)*(0!/1!)
a(2)=(4!/2!)*(1!/2!)
a(3)=(8!/4!)*(2!/4!)
a(4)=(14!/8!)*(4!/8!)
a(5)=(26!/14!)*(8!/14!)
a(6)=(46!/26!)*(14!/26!)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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Edited by Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 05 2004
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STATUS
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approved
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