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A246429 List of c, where c 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. 4
2, 3, 6, 4, 12, 5, 10, 15, 6, 20, 7, 14, 30, 21, 8, 28, 35, 24, 9, 42, 18, 40, 10, 36, 56, 45, 30, 11, 22, 63, 72, 33, 12, 44, 70, 55, 13, 66, 90, 26, 77, 60, 39, 88, 14, 99, 52, 84, 110, 65, 42, 15, 78, 30, 91, 70, 16, 104, 132, 60, 117, 130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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, A247372 for list of b.

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

EXAMPLE

1/6 + 1/3 = 1/2.

1/12 + 1/4 = 1/3.

1/15 + 1/10 = 1/6.

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;

%[[;; , 3]]

CROSSREFS

Cf. A106430, A247372.

Sequence in context: A254047 A049449 A104663 * A305325 A302848 A046202

Adjacent sequences:  A246426 A246427 A246428 * A246430 A246431 A246432

KEYWORD

nonn,look

AUTHOR

Albert Lau, Sep 18 2014

STATUS

approved

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Last modified January 26 17:34 EST 2020. Contains 331280 sequences. (Running on oeis4.)