A106430 Ordered and uniqued length of side opposite the greater of the two angles, one being the double of the other, of a primitive integer-sided triangle.

6, 12, 15, 20, 28, 30, 35, 40, 42, 45, 56, 63, 66, 70, 72, 77, 84, 88, 90, 91, 99, 104, 110, 117, 120, 126, 130, 132, 143, 144, 153, 154, 156, 165, 170, 176, 182, 187, 190, 195, 198, 204, 208, 209, 210, 220, 221, 228, 231, 234, 238, 240, 247, 255, 260, 266, 272, 273, 276, 285, 286, 299

Offset

1,1

Comments

This is also the list of a, where a is positive integer solutions of 1/a+1/b=1/c and a>b>c and gcd[a,b,c]=1, sorted by ascending a, then b. See A247372 for list of b, A246429 for list of c. - Albert Lau, Sep 19 2014

Links

Albert Lau, Table of n, a(n) for n = 1..10539

Formula

Values r*s, where r<s<2r and (r, s)=1.

The other 2 sides are s^2 and r^2-s^2. - Albert Lau, Sep 19 2014

Mathematica

aMax = 300;
Select[Sequence @@@ Table[{m (m + n), n (m + n), m n}, {m, Sqrt[aMax]}, {n, Min[m - 1, aMax/m - m]}], GCD @@ # == 1 &] // Sort;
%[[;; , 1]]
(* Albert Lau, Sep 19 2014 *)

Crossrefs

Cf. A106499-A106506, A106410, A106420, A247372, A246429

Sequence in context: A320142 A063931 A001283 * A106420 A308611 A315619

Adjacent sequences: A106427 A106428 A106429 * A106431 A106432 A106433

Keyword

nonn

Author

Lekraj Beedassy and Ray Chandler, May 09 2005

Status

approved