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.

A247372 List of b, where b 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.

Original entry on oeis.org

3, 4, 10, 5, 21, 6, 14, 24, 7, 36, 8, 18, 55, 30, 9, 44, 60, 33, 10, 78, 22, 65, 11, 52, 105, 70, 39, 12, 26, 112, 136, 42, 13, 60, 119, 80, 14, 102, 171, 30, 126, 85, 48, 152, 15, 180, 68, 133, 210, 90, 51, 16, 114, 34, 140, 95, 17, 168, 253, 76, 198, 230
Offset: 1

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Author

Albert Lau, Sep 14 2014

Keywords

Comments

For any positive integer m and n, a=m(m+n), b=n(m+n), c=m*n is an integer solution for 1/a + 1/b = 1/c.
See A106430 for list of a, A246429 for list of c.

Examples

			1/6 + 1/3 = 1/2.
1/12 + 1/4 = 1/3.
1/15 + 1/10 = 1/6.
		

Crossrefs

Programs

  • 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;
    %[[;;, 2]]