Unbiasing Constant "d4" formula

[Juggler_IN]

I am looking for the formula for d4 constant with values for n = 2 to 5 as 0.9539, 1.5878, 1.9783, 2.2569, ... and so on,

 

[Miner]

The formulas may be found in section 7.0 of this article.

 

[Juggler_IN]

@Miner, it is of D4 and not d4.

 

[Miner]

My mistake. See Minitab Help for the d4 formula.

 

[Juggler_IN]

I am looking for the actual formula and not an approximation. Minitab is giving an approximation formula for N>25.