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Search: id:A002147
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| A002147 |
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Largest prime == 7 mod 8 with class number 2n+1.
(Formerly M4402 N1857)
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+0
3
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| 7, 31, 127, 487, 1423, 1303, 2143, 2647, 4447, 5527, 5647, 6703, 5503, 11383, 8863, 13687, 13183, 12007, 22807, 18127, 21487, 22303, 29863, 25303, 27127
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Apr 14 2008: David Broadhurst says: I computed class numbers for prime discriminants with |D| < 10^9, but stopped when the first case with |D| > 5*10^8 was observed. That factor of 2 seems to me to be a reasonable margin of error, when you look at the pattern of what is included.
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
R. B. Lakein and S. Kuroda, Tables of class numbers h(-p) for fields Q(sqrt(-p)), p<= 465071, Math. Comp., 24 (1970), 491-492.
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LINKS
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David Broadhurst, Table of n, a(n) for n=0..2246 (conjectural; see comment)
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CROSSREFS
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Cf. A002146.
Sequence in context: A036280 A153005 A056909 this_sequence A083420 A036282 A033474
Adjacent sequences: A002144 A002145 A002146 this_sequence A002148 A002149 A002150
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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