A125111 Cubes which do not have a partition as the sum of 2 squares.

27, 216, 343, 1331, 1728, 2744, 3375, 6859, 9261, 10648, 12167, 13824, 19683, 21952, 27000, 29791, 35937, 42875, 54872, 59319, 74088, 79507, 85184, 97336, 103823, 110592, 132651, 157464, 166375, 175616, 185193, 205379, 216000, 238328, 250047

Offset: 1

Author

Artur Jasinski, Nov 21 2006

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000578, A022544, A125084, A125110.

Programs

Mathematica

Select[Range[0, 65]^3, SquaresR[2, # ] == 0 &] (* Ray Chandler, Nov 23 2006 *)

PARI

isA125111(ncube)={ local(a) ; a=0; while(a^2<=ncube, if(issquare(ncube-a^2), return(0) ; ) ; a++ ; ) ; return(1) ; } { for(n=0,200, if(isA125111(n^3), print1(n^3,",") ; ) ; ) ; } \\ R. J. Mathar, Nov 23 2006

Formula

Equals A000578 INTERSECT A022544. - R. J. Mathar, Nov 23 2006

a(n) = A022544(n)^3. - Ray Chandler, Nov 23 2006

Extensions

More terms from R. J. Mathar and Ray Chandler, Nov 23 2006