A178096 Cube of n is equal to sum of four positive distinct squares; n^3=a^2+b^2+c^2+d^2; a>b>c>d>0.

5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57

Offset

1,1

Comments

5^3=8^2+6^2+4^2+3^2, 6^3=10^2+8^2+6^2+4^2, ...

Links

Table of n, a(n) for n=1..48.

Formula

{n: n^3 in A004433}. - R. J. Mathar, Jun 15 2018

Mathematica

z=100; lst={}; Do[a2=a^2; Do[b2=b^2; Do[c2=c^2; Do[d2=d^2; e2=a2+b2+c2+d2; e=e2^(1/3); If[IntegerQ[e], AppendTo[lst, e]], {d, c-1, 1, -1}], {c, b-1, 1, -1}], {b, a-1, 1, -1}], {a, 1, z}]; Union@lst

Crossrefs

Cf. A003294, A005767, A023809, A046100.

Sequence in context: A196026 A191850 A066263 * A246782 A089192 A279195

Adjacent sequences: A178093 A178094 A178095 * A178097 A178098 A178099

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 19 2010

Extensions

Terms > 33 from R. J. Mathar, Jun 15 2018

Status

approved