Graham's number of layer 1 tetration explanation?

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I have a question on how the number of the first layer of the Graham's number ($g_1$) is computed.

From Wikipedia:

http://en.wikipedia.org/wiki/Graham%27s_number#Magnitude

$g_1 = 3\uparrow\uparrow\uparrow\uparrow3 $

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As I understand it, this means that the number of the first layer of the Graham's number $g_1$ is a tetration ($\uparrow\uparrow$) in the form:

$$g_1 = 3^{3^{\cdot^{\cdot^{\cdot^{\cdot^{3}}}}}} = \,{}^{n}3$$

Where $n$ is:

$3\uparrow\uparrow(3\uparrow\uparrow3) = \,{}^{7625597484987}3$

Thus, the height of the tower, is this what Wikipedia says?

If so, now, if:

$$3\uparrow\uparrow3 = \,{}^{3}3 = 3^{3^{3}}$$

$$3\uparrow\uparrow\uparrow3 = 3\uparrow\uparrow(3\uparrow\uparrow3)= \,{}^{3\uparrow\uparrow3}3 = \,{}^{7625597484987}3$$

Why g1 is (as in the posted link):

$$g_1 = 3\uparrow\uparrow\uparrow\uparrow3 = 3\uparrow\uparrow\uparrow(3\uparrow\uparrow\uparrow3)$$

And not:

$$g_1 = 3\uparrow\uparrow\uparrow\uparrow3 = 3\uparrow\uparrow(3\uparrow\uparrow\uparrow3)$$

??? Anyway, why:

$\,\,3\uparrow\uparrow\uparrow(3\uparrow\uparrow\uparrow3)\,\,\,\,\,$ is $\,\,\,\,\,3\uparrow\uparrow(3\uparrow\uparrow(3\uparrow\uparrow ... (3\uparrow\uparrow3)...))$

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The equality $3\uparrow\uparrow\uparrow\uparrow3=3\uparrow\uparrow(3\uparrow\uparrow3)$ is wrong there.

Hyperoperation (from tetration and so on) written in Knuth's notation satisfy the relation: $a\uparrow^nb=a\uparrow^{n-1}a\uparrow^{n-1}a\uparrow^{n-1}\dots \uparrow^{n-1}a$ where $n$ is the number of arrows, and $\uparrow^{n-1}$ is iterated b times.

So the first layer which is $3\uparrow\uparrow\uparrow\uparrow\uparrow2$ or (more usually) $3\uparrow\uparrow\uparrow\uparrow3$ is equal to:

$3\uparrow\uparrow\uparrow\uparrow3=3\uparrow\uparrow\uparrow3\uparrow\uparrow\uparrow3=3\uparrow\uparrow\uparrow(3\uparrow\uparrow3\uparrow\uparrow3)=3\uparrow\uparrow\uparrow(3\uparrow\uparrow7625597484987)$

So after you exponentiate 3 to itself 7625597484987 times you get how many times you have to tetrate 3 to itself, and that's only the first layer!