

A028944


Numerator of xcoordinate of (2n+1)*P where P is the generator for rational points on the curve y^2 + y = x^3  x.


2



0, 1, 1, 5, 20, 116, 3741, 8385, 239785, 59997896, 1849037896, 270896443865, 16683000076735, 2786836257692691, 3148929681285740316, 342115756927607927420, 280251129922563291422645, 804287518035141565236193151
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,4


LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..105
B. Mazur, Arithmetic on curves, Bull. Amer. Math. Soc. 14 (1986), 207259; see p. 225.


FORMULA

P = (0, 0), 2P = (1, 0); if kP = (a, b) then (k+1)P = (a' = (b^2  a^3)/a^2, b' = 1 b*a'/a).
a(n) = A028940(2n+1).  Seiichi Manyama, Nov 20 2016


EXAMPLE

7P = (5/9, 8/27).


CROSSREFS

Cf. A028940, A028945.
Sequence in context: A207972 A117736 A258665 * A054720 A208941 A209069
Adjacent sequences: A028941 A028942 A028943 * A028945 A028946 A028947


KEYWORD

sign,frac


AUTHOR

N. J. A. Sloane


STATUS

approved



