Lagrange polynomial 'hello world!'

helloworld.js

const greet = () => {
    const L = (x) => -
        (       1699 / 831600 * x ** 11) +
        (      37339 / 302400 * x ** 10) -
        (     589129 / 181440 * x **  9) +
        (    1965121 /  40320 * x **  8) -
        (   17402561 /  37800 * x **  7) +
        (   20479411 /   7200 * x **  6) -
        (  233153797 /  20160 * x **  5) +
        ( 3667222847 / 120960 * x **  4) -
        (22023397139 / 453600 * x **  3) +
        ( 2133337579 /  50400 * x **  2) -
        (  414933319 /  27720 * x **  1) +
        (          8 /      1 * x **  0);

    let n = 0;
    let greetingString = '';

    for (let i = 0; i <= 11; i++) {
        let l = Math.round(L(i));
        n += l;
        greetingString += String.fromCharCode(96 + n);
    }
    return greetingString;
}

console.log(greet());