A144858 Numbers of the form 2^(n-1)*(2^n - 1) which aren't perfect numbers.

0, 1, 120, 2016, 32640, 130816, 523776, 2096128, 8386560, 134209536, 536854528, 2147450880, 34359607296, 549755289600, 2199022206976, 8796090925056, 35184367894528, 140737479966720, 562949936644096, 2251799780130816