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A279687
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a(0) = 1, a(n) is the least prime factor of a(n-1)^2+1 that has not previously appeared in the sequence for n > 0.
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0
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1, 2, 5, 13, 17, 29, 421, 401, 37, 1877, 41
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OFFSET
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0,2
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LINKS
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EXAMPLE
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a(7) is a prime factor of a(6)^2+1 = 421^2 + 1 = 177242, which factors as 2*13*17*401. 2, 13, and 17 have already appeared in the sequence, so a(7) = 401.
a(10)^2+1 = 882 = 2 * 29^2. Both 2 and 29 have already appeared in the sequence, so it terminates.
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CROSSREFS
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KEYWORD
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nonn,fini,full
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AUTHOR
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STATUS
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approved
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