1.
The value of limn1+23+4+56++(3n2)+(3n1)3n2n4+4n+3n4+5n+4\lim\limits_{n \to \infty} \frac{1 + 2 - 3 + 4 + 5 - 6 + \ldots + (3n - 2) + (3n - 1) - 3n}{\sqrt{2n^4 + 4n + 3} - \sqrt{n^4 + 5n + 4}} is