A267189 (Cubes of positive numbers) that are not the sum of three nonzero squares.

1, 8, 64, 343, 512, 3375, 4096, 12167, 21952, 29791, 32768, 59319, 103823, 166375, 216000, 250047, 262144, 357911, 493039, 658503, 778688, 857375, 1092727, 1367631, 1404928, 1685159, 1906624, 2048383, 2097152, 2460375, 2924207, 3442951, 3796416, 4019679, 4657463, 5359375, 6128487

Offset

1,2

Comments

This is the intersection of A004214 and A000578.

The original definition of A134739 was ambiguous - this is the second way it could have been interpreted. The other way, now the official definition of A134739, being "Cubes of (positive numbers that are not the sum of three nonzero squares)".

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Prog

(PARI) is(n) = { my(a, b) ; a=1; while(a^2+1<n, b=1 ; while(b<=a && a^2+b^2<n, if(issquare(n-a^2-b^2), return(1) ) ; b++ ; ) ; a++ ; ) ; return(0) ; }
for(n=1, 200, if(!is(n^3), print1(n^3, ", "))); \\ Altug Alkan, Jan 18 2016

Crossrefs

Cf. A000578, A004214, A134739.

Sequence in context: A344854 A223843 A356703 * A181480 A223948 A224151

Adjacent sequences: A267186 A267187 A267188 * A267190 A267191 A267192

Keyword

nonn

Author

N. J. A. Sloane, Jan 18 2016

Extensions

More terms from Altug Alkan, Jan 18 2016

Status

approved