Numbers k for which omega(k)*omega(k + 1)*omega(k + 2) = 2 where omega = A001221.

Terms

a(0) =4a(1) =5a(2) =6a(3) =8a(4) =9a(5) =11a(6) =15a(7) =16a(8) =17a(9) =23a(10) =25a(11) =27a(12) =31a(13) =47a(14) =71a(15) =79a(16) =81a(17) =107a(18) =127a(19) =191a(20) =241a(21) =431a(22) =1151a(23) =2591a(24) =8191a(25) =131071a(26) =139967a(27) =472391a(28) =524287a(29) =786431