Lucky 7 side bet

Noticed a Lucky 7 side bet at Altira Macau. Would anyone happen to know the house edge?

Believe the Blackjack game is 6 decks. The odd thing is that it pays nothing if you get a single 7. Here's the pay table

Unsuited Pair of 7s 50 to 1
Suited Pair of 7s 150 to 1
3rd card is a different suit of 7 500 to 1
3rd card is the same suit of 7 5000 to 1

For the 3 card Lucky 7s, the 7s need to be split.

Thanks for your help in advance.

I did some small calculations for the house edge of the Lucky 7 side bet at Altira Macau:

The probability of getting an unsuited pair of 7s is (32/311) * (16/310) = 0.1654%.
The probability of getting a suited pair of 7s is (8/311) * (7/310) = 0.0580%.
The probability of getting a 3rd card of a different suit of 7 is (32/311) * (16/310) * (280/309) = 0.1431%.
The probability of getting a 3rd card of the same suit of 7 is (8/311) * (7/310) * (6/309) = 0.0011%.

To calculate the house edge, we need to subtract the sum of these probabilities from 1, and then multiply by the corresponding payouts:

House edge = (1 - (0.001654 + 0.000580 + 0.001431 + 0.000011)) * (50 + 150 + 500 + 5000)

Dmitri, after doing the math you laid out, I get (-19.9532). So are you saying it's a house edge of 19.9532%?

MGM casinos in Macau are also rolling out this Lucky 7 side bet. They have one slightly different rule compared to the the Melco casinos.

For the 3 card Lucky 7's, the 3rd 7 can come after a hit or a split.

How would this change the house edge?