

A028941


Denominator of Xcoordinate of n*P where P is generator for rational points on curve y^2+y = x^3x.


1



1, 1, 1, 1, 4, 1, 9, 25, 49, 16, 529, 841, 3481, 16641, 98596, 4225, 2337841, 13608721, 67387681, 264517696, 6941055969, 12925188721, 384768368209, 5677664356225, 61935294530404, 49020596163841, 16063784753682169
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OFFSET

1,5


COMMENTS

Squares of terms in A006769 (or A006720).


REFERENCES

G. Everest, A. J. van der Poorten, I. Shparlinski and T. Ward, Recurrence Sequences: Examples and Applications, AMS Monographs, 2003
B. Mazur, Arithmetic on curves, Bull. Amer Math. Soc. 14 (1986), 207259; see p 225.


LINKS

Table of n, a(n) for n=1..27.


FORMULA

This sequence satisfies the quadratic recurrence relation a(n)a(n6)=a(n1)a(n5)+2a(n2)a(n4)+2a(n3)^2 which is a generalized Somos6 relation.  Graham Everest (g.everest(AT)uea.ac.uk), Dec 16 2002
P=(0, 0), 2P=(1, 0), if kP=(a, b) then (k+1)P=(a'=(b^2a^3)/a^2, b'=1b*a'/a).


CROSSREFS

Sequence in context: A143763 A128626 A193963 * A176080 A065045 A185088
Adjacent sequences: A028938 A028939 A028940 * A028942 A028943 A028944


KEYWORD

nonn


AUTHOR

N. J. A. Sloane.


STATUS

approved



