C (gcc), 85 81 75 bytes
Saved 4 bytes and then 6 bytes thanks to @ceilingcat's re-ordering of assignments
r[5];f(n){r[1]=(n=(n-(*r=n*n*n))/6+1)*n*n--;r[3]=r[4]=-n*n*n;r[2]=--n*n*n;}
C (gcc),
vazt
- 301
- 1
- 4