Sums of three Mersenne primes.

Terms

a(0) =9a(1) =13a(2) =17a(3) =21a(4) =37a(5) =41a(6) =45a(7) =65a(8) =69a(9) =93a(10) =133a(11) =137a(12) =141a(13) =161a(14) =165a(15) =189a(16) =257a(17) =261a(18) =285a(19) =381a(20) =8197a(21) =8201a(22) =8205a(23) =8225a(24) =8229a(25) =8253a(26) =8321a(27) =8325a(28) =8349a(29) =8445