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 A002146 Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1. (Formerly M4377 N1841) 7
 7, 23, 47, 71, 199, 167, 191, 239, 383, 311, 431, 647, 479, 983, 887, 719, 839, 1031, 1487, 1439, 1151, 1847, 1319, 3023, 1511, 1559, 2711, 4463, 2591, 2399, 3863, 2351, 3527, 3719 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Conjecture: a(n) < A002148(n) for all n >= 1. - Jianing Song, Jul 20 2022 REFERENCES D. A. Buell, Binary Quadratic Forms. Springer-Verlag, NY, 1989, pp. 224-241. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS David Broadhurst and T. D. Noe, Table of n, a(n) for n = 0..28603 D. Shanks, Review of 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. PROG (PARI) a(n) = forprime(p=2, oo, if ((p % 8) == 7, if (qfbclassno(-p) == 2*n+1, return(p)))); \\ Michel Marcus, Jul 20 2022 CROSSREFS Cf. A002147, A002148, A060651, A002143 (class numbers). Sequence in context: A185007 A308732 A139035 * A336092 A184882 A073577 Adjacent sequences: A002143 A002144 A002145 * A002147 A002148 A002149 KEYWORD nonn AUTHOR N. J. A. Sloane, Mira Bernstein STATUS approved

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Last modified May 20 03:57 EDT 2024. Contains 372703 sequences. (Running on oeis4.)