Logging of processes killed by OOM Killer is not consistent as to where logged on different Linux operating systems.
The following grep command will assist in finding logged entries:
# run on Debian 10.7 - illustrates logging on Debian 10 is to /var/log/kern.log grep -arRnFi 'Killed process' /var/log/ /var/log/kern.log.1:51188:Dec 30 20:37:21 omk-vm8-debian10 kernel: [ 451.435966] Killed process 2586 (VBoxHeadless) total-vm:3389340kB, anon-rss:0kB, file-rss:2229280kB, shmem-rss:0kB /var/log/kern.log.1:52870:Dec 30 23:35:33 omk-vm8-debian10 kernel: [ 8935.819561] Killed process 10156 (VBoxHeadless) total-vm:3813276kB, anon-rss:0kB, file-rss:2653120kB, shmem-rss:0kB /var/log/kern.log.1:54340:Dec 31 22:30:15 omk-vm8-debian10 kernel: [81770.629634] Killed process 23906 (VBoxHeadless) total-vm:3772300kB, anon-rss:0kB, file-rss:2610232kB, shmem-rss:0kB /var/log/kern.log.1:57045:Jan 1 09:51:35 omk-vm8-debian10 kernel: [ 7685.370394] Killed process 12314 (VBoxHeadless) total-vm:4207164kB, anon-rss:0kB, file-rss:3042256kB, shmem-rss:0kB /var/log/kern.log.1:59728:Jan 1 11:36:45 omk-vm8-debian10 kernel: [ 4532.997571] Killed process 18016 (VBoxHeadless) total-vm:4563512kB, anon-rss:0kB, file-rss:3074508kB, shmem-rss:0kB