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

1,1

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]

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 *)

Crossrefs

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

Sequence in context: A115534 A138030 A104964 * A344804 A003825 A114259

Adjacent sequences: A018784 A018785 A018786 * A018788 A018789 A018790

Keyword

nonn

Author

David W. Wilson, Aug 15 1996

Status

approved