The explanation for the very slight, out-of-order serial numbers is most likely due to several serialized stacks of birth certificates that were most likely made available at different hospitals.  

Eleanor Nordyke is on record saying that she thinks her twins got slightly lower numbers because she went into the hospital Aug. 4, 1961, and was in labor for 20 hours before she delivered. She speculates that Ann Dunham came in after her and was given a later number, even though Dunham’s baby was born earlier. Nordyke’s twins were not born until the afternoon of the next day. 

Not worth losing sleep over, unless maybe your initials are DT. But he only gets 4 hours of sleep a night anyway, or “so I've heard, I'm just saying.”  Speaking of transparency, we are still waiting for his tax returns. He's taking a big gamble. I'd rather have a taco truck on every street corner, instead of a casino on every street corner. ;-)