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A204098
Numbers n such that there is a triangle with area 1 and rational sides, and one side is the positive integer n.
0
4, 5, 6, 8, 12, 14, 16, 17, 20, 21, 22, 30, 31, 32, 33, 35, 37, 40, 41, 42
OFFSET
1,1
COMMENTS
n is present in the sequence just in case the elliptic curve Y^2 = (n^4+4)*X^4 + 8*n^2*X^3 - 2*(n^4-4)*X^2 - 8*n^2*X + (n^4+4) has positive rank over the rationals. Note (X,Y)=(1,4) is a point on the curve.
Some entries in this sequence and some omissions from the sequence are based on standard conjectures about elliptic curves.
EXAMPLE
5 is in the sequence because the rational triangle with sides (a, b, c) = (4097/858, 5, 401/858) has area 1 and one side is 5.
CROSSREFS
Sequence in context: A030590 A047430 A360448 * A115838 A310572 A310573
KEYWORD
nonn,hard
AUTHOR
STATUS
approved