# [C (gcc)], <strike>85</strike> <strike>81</strike> 75 bytes

Saved 4 bytes and then 6 bytes thanks to @ceilingcat's re-ordering of assignments

<!-- language-all: lang-c -->

    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;}

[Try it online!][TIO-jfl6r5s7]

[C (gcc)]: https://gcc.gnu.org/
[TIO-jfl6r5s7]: https://tio.run/##VY/PDoIwDMbP8BSLicnGtgj@O4h7krmDQWY4UEzhJOHZsZ1ezJrla39t@rWxz6ZZV/SnUEcJakZfBSeBwsoCHRT0lNqddaVYWlujPwSH/hicTZQKe9K/ZFn7ewdS5XOexQFlB5MA4YStyrImdXXiq7RWYmrHiZbW@ZInmZrTaN/2YztJNKUZu3c7RGaqOFFvFtNI9kIqRbkBt31cxPbxF46@G2wMGPRlMHyVYZ@G3Rt2n4BmoBloBpoB21k/ "C (gcc) – Try It Online"