A369334 Positive integers m such that there exist distinct pairs (a,b) and (c,d) with a <= b, c <= d, gcd(a,b,c,d) = 1, and m = a*b*(c+d) = (a+b)*c*d.

72, 144, 168, 360, 450, 480, 864, 990, 1200, 1404, 1568, 1600, 1800, 2040, 2160, 2520, 2646, 3150, 3360, 3600, 3780, 4050, 4800, 5184, 5400, 5520, 5880, 5940, 6720, 7056, 7200, 7350, 7800, 7938, 8550, 8640, 8694, 8712, 8976, 9408, 9450, 9504, 10416, 11550, 11760, 12000, 12600, 12960, 13230, 14112, 14850, 15288, 16128, 16200, 16560, 16562, 17640, 18000, 18144, 18216

Offset

1,1

Comments

Note that a*b*(c+d) = (a+b)*c*d is equivalent to 1/a + 1/b = 1/c + 1/d.

Links

Table of n, a(n) for n=1..60.

Crossrefs

Cf. A369333.

Sequence in context: A345794 A157336 A369333 * A060661 A050495 A137883

Adjacent sequences: A369331 A369332 A369333 * A369335 A369336 A369337

Keyword

nonn

Author

Max Alekseyev, Jan 20 2024

Status

approved