A178096 - OEIS

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.

%I #9 Dec 26 2023 11:57:59

%S 5,6,7,9,10,11,13,14,15,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,

%T 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,49,50,51,52,53,54,55,56,

%U 57

%N 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.

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

%F {n: n^3 in A004433}. - _R. J. Mathar_, Jun 15 2018

%t 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

%Y Cf. A003294, A005767, A023809, A046100.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, May 19 2010

%E Terms > 33 from _R. J. Mathar_, Jun 15 2018