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A317053 Complete list of solutions to y^2 + y = x^3 - 525x + 10156 with y > 0; sequence gives positive y values. 0
31, 74, 76, 87, 112, 121, 319, 562, 679, 1462, 3937, 5312, 7987, 18312, 61312, 66712, 2597287 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This equation gives the elliptic curve (W46) studied by Stroeker and de Weger. This curve has rank 3 with generators P1 = (25, 112), P2 = (-20, 112) and P3 = (70, 562). The list gives all integer points with y > 0 in this curve.

Each positive y corresponds to a negative solution -y - 1, so that the sequence gives all y values of solutions.

Some y values corresponds to three solutions. For y = 87, we have x = -25, 5 or 20. For y = 112, we have x = -20, -5 or 25. Any other value of y corresponds to a unique solution.

This equation can be transformed to A000332(n) = A000579(m) by x = (15/2)m^2 - (75/2)m + 25 and y = (225/2)n^2 - (675/2)n + 112. Hence, A000332(n) = A000579(m) (n >= 4, m >= 6) has no integer solutions other than (n, m)= (4, 6) and (10, 10).

LINKS

Table of n, a(n) for n=1..17.

Roelof J. Stroeker and Benjamin M. M. de Weger, Elliptic binomial diophantine equations, Math. Comp. 68 (1999), 1257-1281.

EXAMPLE

a(1) = 31: (-29)^3 - 525 * (-29) + 10156 = 996 = 31 * 32.

PROG

(SageMath) EllipticCurve([0, 0, 1, -525, 10156]).integral_points()

CROSSREFS

Cf. A303615 (x values)

Cf. A029728 (the complete list of solutions x to y^2 = x^3 + 17), A102461 (the complete list of solutions n to A000217(n) = A027568(m)).

Sequence in context: A163428 A130468 A068917 * A009408 A165615 A142408

Adjacent sequences:  A317050 A317051 A317052 * A317054 A317055 A317056

KEYWORD

nonn,fini,full

AUTHOR

Tomohiro Yamada, Jul 20 2018

STATUS

approved

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Last modified June 1 02:09 EDT 2020. Contains 334758 sequences. (Running on oeis4.)