Finding a formula for this sequence $-8, -14, 8, 14, -8, -14, 8, 14$

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I couldn't find this on the whole internet. My life depends on solving this. Please help. I must write a formula for this sequence $-8, -14, 8, 14, -8, -14, 8, 14$.

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Consider for an indice $n$ that if n is divisible by 2 the absolute value of your sequence is 14, else the absolute value is 8.

Next if an indice $n$ can be represented by $4k-1$ or $4k$ for $k \in \Bbb N$ then the sequence value is positive, else the sequence value is negative.

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$f(x)=14 \cos (\pi x/2)-8 \sin(\pi x/2)$ does it, for $x=1,2,3,4,\cdots .$