A259682 Let m = A062695(n); a(n) is value of u in decomposition of m defined in Comments.

1, 1, 5, 1, 23, 1, 7, 1, 1, 3, 1, 1, 257, 5, 1, 23, 1, 1, 1, 1, 1, 1, 79, 1, 71, 1, 17, 457, 1, 1, 1, 1, 1, 7, 21, 1, 1, 1, 1, 103, 1, 17, 1, 1, 1, 1, 1, 1, 1, 1, 5, 47, 199, 1, 7, 37, 1081, 13, 3, 17, 3, 1, 3, 1, 7, 167, 19, 1, 1, 239, 1, 1, 1, 1, 1, 1, 1, 103

Offset

1,3

Comments

Let m = A062695(n). Write m*y^2 = x^3 - x as m*square = A*B*(A-B)*(A+B) where A and B are the numerator and denominator of x. Then A, B, A-B, A+B have the form s*a^2, t*b^2, u*c^2, v*d^2 for some decomposition of m as s*t*u*v and some natural numbers a,b,c,d. These eight numbers are given in A259680-A259687.

Links

Table of n, a(n) for n=1..78.

G. Kramarz, All congruent numbers less than 2000, Math. Annalen, 273 (1986), 337-340.

G. Kramarz, All congruent numbers less than 2000, Math. Annalen, 273 (1986), 337-340. [Annotated, corrected, scanned copy]

Crossrefs

Cf. A003273, A006991, A062695, A259680-A259687.

Sequence in context: A051929 A347487 A213118 * A286897 A167572 A147476

Adjacent sequences: A259679 A259680 A259681 * A259683 A259684 A259685

Keyword

nonn

Author

N. J. A. Sloane, Jul 04 2015

Extensions

More terms from Jinyuan Wang, Jan 01 2021

Status

approved