How to determine "Predictable Name" of network interface

Details of the naming scheme are in the source code: udev/udev-builtin-net_id.c. Previously, this had a nice readable comment block explaining things, but since a refactor removed that a better reference is at man systemd.net-naming-scheme.

Some common schemes are PCI physical, PCI hotplug, and onboard. Your enp interface suggests physical.

Stripping out exotic and irrelevant bits from the comments leaves these rules:

 * Two character prefixes based on the type of interface:
 *   en — Ethernet
 *
 * Type of names:
 *   [P<domain>]p<bus>s<slot>[f<function>][n<phys_port_name>|d<dev_port>]
 *                                         — PCI geographical location
 *
 * All multi-function PCI devices will carry the [f<function>] number in the
 * device name, including the function 0 device.
 *
 *
 * When using PCI geography, The PCI domain is only prepended when it is not 0.

That PCI bus name is formatted as domain:bus:slot.function.

Assuming it is not a multifunction device, pci@0000:41:00.0 appears as enp65s0, since hex 41 converts to decimal 65.