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Write fundamental unit for real quadratic field of discriminant n as x + y*omega; sequence gives values of x for n == 2 mod 4.
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%I #12 Apr 14 2019 11:00:09

%S 1,5,3,15,197,5,11,35,37,13,24335,99,63,65,251,43,53,9,10405,2143295,

%T 101,4005,21,1025,306917,11,57,145925,47,143,145,21295,7743,

%U 1700902565,13,1451,1601,27,7501,52021,195,3141,59535,29

%N Write fundamental unit for real quadratic field of discriminant n as x + y*omega; sequence gives values of x for n == 2 mod 4.

%C Entries are indexed by values of n from A039956.

%D R. A. Mollin, Quadratics, CRC Press, 1996, Tables B1-B3.

%H S. R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/">Class number theory</a>

%H Steven R. Finch, <a href="/A000924/a000924.pdf">Class number theory</a> [Cached copy, with permission of the author]

%t NumberFieldFundamentalUnits[ Sqrt[#] ][[1, 2, 1]] & /@ Select[Range[2, 210, 2], SquareFreeQ] (* _Jean-François Alcover_, Jul 09 2013 *)

%Y Cf. A053370-A053375.

%K nonn,easy,nice

%O 0,2

%A _N. J. A. Sloane_, Jan 06 2000