I just ran this:
% darkcoind masternode list | sort | uniq -c | grep --color -v '^ *1'
3 "37.46.114.158:9999" : 1,
2 "37.46.114.244:9999" : 1,
2 "37.46.114.245:9999" : 1,
2 "37.46.114.58:9999" : 1,
2 "37.46.114.66:9999" : 1,
2 "37.46.114.76:9999" : 1...