Wash sale deductible?

This is a wash sale violation and the loss is not deductible until the replacement shares are disposed of.

A wash sale violation (WSV) occurs you purchase a “substantially identical” security or option within a 60 day window around the date that you realize a loss. That's 30 days before and 30 days after the loss. All that means is that the lost is deferred as you increase the cost basis of the second purchase by the amount of the loss. When you close the second position cleanly (assuming no additional WSVs), you get to deduct the original loss.

You can have any number of wash sale violations in the same or multiple securities and if you close all involved positions by the end of the year and do not open a "substantially identically" position in the next 30 days after realizing the loss, you can claim all losses in the current tax year.

Let me illustrate by a minor change to your dates.

Day 1: I purchase Stock A.

Day 105: I purchase more Stock A.

Day 118: I sell 1/2 of total investment for a loss.

On day 105, you are thinking "I might want to sell my Stock A to claim a loss, but I like the stock long term. In fact, I'd be ok to buy more, and I do. 13 days later you sell the day one shares at a loss. The 'replacement shares' were bought +/- 30 days of that sale at a loss. Wash sale.

This leads me to a strange observation. Had you bought 100 shares day 1, and sold 50 at a loss day 5, you might (I am not 100% certain) still have a wash sale issue.