srcset-generator.js

sizes(300, 1360, 0.15)

function sizes(start, stop, tol = 0.1) {
    if (start === stop) return [start]

    const resolutions = []
    while (start < stop) {
        resolutions.push(Math.ceil(start))
        start *= 1 + tol * 2
    }

    if (resolutions.at(-1) < stop) {
        resolutions.push(stop)
    }

    return resolutions
}