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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A057229 a(n) = a*b = x*y with (a-b) = (x+y) = A020882(n) (a>b, a>0, b>0, x>0, y>0), gcd(a, b) = gcd(x, y) = 1.

Original entry on oeis.org

6, 30, 60, 84, 210, 210, 180, 630, 330, 504, 924, 1320, 546, 1386, 1560, 2340, 990, 2730, 840, 2574, 4620, 1224, 1716, 3570, 5610, 7140, 4290, 1710, 5016, 7956, 7980, 2730, 7854, 10374, 2310, 11970, 6630, 10920, 12540, 4080, 3036, 11856, 8970
Offset: 0

Views

Author

Naohiro Nomoto, Sep 19 2000

Keywords

Comments

The quadratics in X, X^2 - S*X -+ P, where S=A020882(n), P=A057229(n) are each factorizable into two factors, all four being distinct: X^2 - S*X - P = (X - a)*(X + b). X^2 - S*X + P = (X - x)*(X - y). - Lekraj Beedassy, Apr 30 2004
Areas of primitive Pythagorean triangles sorted on hypotenuse A020882, then on perimeter A093507. - Lekraj Beedassy, Aug 18 2006

Examples

			E.g. a(1)=6=6*1=3*2, (6-1)=(3+2)=5=A020882(1), gcd(6,1)=gcd(3,2)=1
		

Crossrefs

A093508 Semiperimeter of primitive Pythagorean triangles sorted on hypotenuse A020882(n).

Original entry on oeis.org

6, 15, 20, 28, 35, 42, 45, 63, 66, 72, 77, 88, 99, 91, 104, 117, 110, 130, 120, 143, 165, 156, 153, 170, 187, 204, 195, 190, 221, 209, 228, 210, 238, 247, 266, 231, 255, 273, 285, 304, 276, 299, 322, 336, 345, 323, 357, 368, 325, 350, 342, 391, 400, 414, 425
Offset: 1

Views

Author

Lekraj Beedassy, May 14 2004

Keywords

Comments

For ordered semiperimeter of primitive Pythagorean triangles see A020886.

Formula

a(n)=A093507/2.
Showing 1-2 of 2 results.