Answer by Qwertiy for All about basic binary

Javascript, ES6, 118*.75 = 88.5 110*.75 = 82.5

f=x=>{res={};for(b=2;b<=x;++b)if(!+(res[b]=(c=x=>x%b<2?x?c(x/b|0)+""+x%b:"":"*")(x)))delete res[b];return res}

Previous version:

f=x=>{res={};for(q=2;q<=x;++q)if(!+(res[q]=(c=(x,b)=>x%b<2?x?c(x/b|0,b)+""+x%b:"":"*")(x,q)))delete res[q];return res}

Check:

f(82000)Object { 2: "10100000001010000", 3: "11011111001", 4: "110001100", 5: "10111000", 81999: "11", 82000: "10" }