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A084955
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Initial prime of a prime chain of length n under the iteration x->2x+5.
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7
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2, 3, 7, 13, 13, 13, 541, 4594309, 64649503, 7577449963, 2005324830163, 39676048812109, 272235769110157, 494535766350049
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| This is a special case of prime chains generated by f(x) = cx + d.
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REFERENCES
| D. H. Lehmer, On certain chains of primes, Proc. London Math. Soc. (3) 14a 1965 183-186.
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EXAMPLE
| a(3)=7 since 7, 2*7+5=19 and 2*19+5=43 are primes.
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CROSSREFS
| Cf. A084954.
Sequence in context: A084423 A068134 A081256 * A026472 A101739 A141633
Adjacent sequences: A084952 A084953 A084954 * A084956 A084957 A084958
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KEYWORD
| nonn,more
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AUTHOR
| W. Edwin Clark (eclark(AT)math.usf.edu), Jun 14 2003
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EXTENSIONS
| More terms from Don Reble (djr(AT)nk.ca), Nov 07 2007
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