JSFiddle - React, Tailwind, and code Playground

HTML

<div id="fdiv">
    <label>f(<input/>)</label><button>calc</button>
</div>
<div id="gdiv">
    <label>g(<input/>)</label><button>calc</button>
</div>

JavaScript

function f(n){m=n/(n&-n);for(r=s=i=0;;){if(!(i%m)){r+=s;s=0;if(i==n)return r;}s=s*n+i++}}

function g(n){c=n&-n;for(s=i=0;i<n/c;++i)s+=Math.pow(n,n/c-i-1)*(c*i+(c-1)*n/2);return s}

document.querySelector("#fdiv button").onclick = function () {
    alert(f(+document.querySelector("#fdiv input").value));
};

document.querySelector("#gdiv button").onclick = function () {
    alert(g(+document.querySelector("#gdiv input").value));
};