If there is a connection, I would expect it to be related to the fact that the [$j$ invariant][1] is connected to both [Moonshine][2] and to [class field theory][3]. Note that 7, 11, 19, 43, 67, and 163 are all the absolute values of odd discriminants with class number 1. (Strangely, 3 is missing from the list! Otherwise the list is complete.) [1]: https://en.wikipedia.org/wiki/J-invariant [2]: https://en.wikipedia.org/wiki/J-invariant#Moonshine [3]: https://en.wikipedia.org/wiki/J-invariant#Class_field_theory_and_j