cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A259686 Let m = A062695(n); a(n) is value of c in decomposition of m defined in Comments.

Original entry on oeis.org

1, 3, 1, 17, 1, 3, 1, 3, 5, 1, 5, 7, 7, 3, 1, 1, 5, 11, 1, 15, 5, 7, 1, 1, 1, 1, 1, 7, 1, 9, 15, 1, 1, 1, 1, 5, 9, 7, 17, 1, 97, 7, 799, 11, 49, 17, 1, 3, 1, 1, 63, 1, 1, 55, 161, 3, 1, 1, 1, 1, 1, 161, 7, 1, 1, 1, 1, 7, 3783, 1, 7, 1697, 21, 319, 21, 911, 3, 1
Offset: 1

Views

Author

N. J. A. Sloane, Jul 04 2015

Keywords

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.

Crossrefs

Extensions

More terms from Jinyuan Wang, Jan 01 2021

A337704 Pythagorean primes that are not congruent numbers.

Original entry on oeis.org

17, 73, 89, 97, 113, 193, 233, 241, 281, 337, 401, 409, 433, 449, 521, 569, 577, 593, 601, 617, 641, 673, 769, 809, 857, 881, 929, 937, 953, 977, 1009, 1033, 1049, 1097, 1129, 1153, 1193, 1289, 1297, 1361, 1409, 1433, 1481, 1489, 1553, 1601, 1609, 1657, 1697, 1721, 1753
Offset: 1

Views

Author

Jani Melik, Sep 16 2020

Keywords

Examples

			17 is a Pythagorean prime and is not congruent because it is not the area of a right triangle with rational sides. So 17 is a term.
		

Crossrefs

Intersection of A002144 and A165564.
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