As kids back in Queens, we'd count almost anything. Within reason.
There was a pirate on 1620 out of Brooklyn (WFAT); with no X-Band then they got out a bit past their nominal 'COL'. Some radio club people might know their wattage.
'WEJP', a pirate on 1460 from South Queens I found one night, would sail across Jamaica Bay to the Rockaways, but we didn't count them on 1460. I called a buddy, who thought that 1460 was a curious choice for a NYC pirate to call home. He found their louder parent signal on 730. Xmitr leak? Bad filtering? NO filtering? One of the lads found a weak second (?) harmonic around 2920.
(We didn't have LED dials then, but we once *did* paint a substantial-looking second base in the street ..... some northbound truck came by and promptly installed dimming harmonics of it halfway to 109th Avenue. And since we didn't use those second bases, we didn't count WEJP 1460. Or 2920. Or 5840 ......)
Further East on Long Island was a real off-frequency (but on-topic) mystery: a weak WGLI 1290 signal on analog 1160 or 1162. Day and night -- with the same wicked directional characteristics as the licensed signal. In the car, on portables, from table radios.
There was only one other AM on at night on the entire Island (WGBB 1240) and that was in Nassau County. So it couldn't've been those mixing and spur effects like with the horizons of red blinking lights in the NJ Meadowlands.
Even though the WGLI 1160 signal was there for a few years, we never did come up with a mathematical answer. It HAD to've originated at the main 1290 site, though, no?