A018787 Numbers that are the sum of two positive cubes in at least three ways (all solutions).

87539319, 119824488, 143604279, 175959000, 327763000, 700314552, 804360375, 958595904, 1148834232, 1407672000, 1840667192, 1915865217, 2363561613, 2622104000, 3080802816, 3235261176, 3499524728, 3623721192, 3877315533, 4750893000, 5544709352, 5602516416

Offset: 1

Author

David W. Wilson, Aug 15 1996

Keywords

• nonn

References

• J. Leech, Some solutions of Diophantine equations, Proc. Camb. Phil. Soc., 53 (1957), 778-780.
• R. K. Guy, Unsolved Problems in Number Theory, D1.

Links

• Ray Chandler, Table of n, a(n) for n=1..100000
• Uwe Hollerbach, Taxi, Taxi! [Original link, broken]
• Uwe Hollerbach, Taxi, Taxi! [Replacement link to Wayback Machine]
• Uwe Hollerbach, Taxi! Taxi! [Cached copy from Wayback Machine, html version of top page only]

Crossrefs

Cf. A001235, A003825, A023051, A025294, A025398, A344804.

Programs

Mathematica

a=Sort[Flatten@Table[n^3+m^3,{m,2000},{n,m-1,1,-1}]];f3[l_]:=Module[{t={}},Do[If[l[[n]]==l[[n+2]],AppendTo[t,l[[n]]]],{n,1,Length[l]-2}];t];f3[a] (* Vladimir Joseph Stephan Orlovsky, Jan 21 2012 *)