interface LazySequence<T> {
    value: T;
    next(): LazySequence<T>;
}

// Implement the function:
function initSequence<T>(transform: (value: T) => T): (initialValue: T) => LazySequence<T> {
    function _next(v:T): LazySequence<T> {
        return {
            value: v,
            next: () => _next(transform(v))
        }
    }
    return initialValue => _next(initialValue)
}