A081779 Ordered m for which m = k^3*a*b*(a^4 - b^4) determine (unique) solution triples(k,a,b), where k=1,2,3,... and (a,b) are coprime pairs, not both odd (i.e., of opposite parity).

30, 240, 390, 810, 1020, 1920, 2100, 3120, 3750, 6090, 6480, 7380, 7770, 8160, 10290, 10530, 15360, 16800, 20130, 21870, 24960, 27540, 30000, 32760, 33390, 39930, 46410, 48720, 48750, 51840, 56700, 59040, 60060, 62160, 65280, 65910, 82320, 84240, 94920, 96360

Offset: 1

Author

Lekraj Beedassy, Apr 10 2003

Keywords

• nice
• nonn

Comments

Also called Saint-Exupery numbers.

Links

• N. des Vallieres and F. D'Agay, Le Probleme du Pharaon.

Crossrefs

Cf. A057096.

Programs

Mathematica

Import["https://oeis.org/A057096/b057096.txt", "Table"][[;;40, 2]]/2 (* Jean-François Alcover, Nov 21 2019 *)

Formula

a(n) = A057096(n)/2.

Extensions

Corrected and extended by Jean-François Alcover, Nov 21 2019