Mersenne numbers for which the product of the digits is not zero.

Terms

a(0) =1a(1) =3a(2) =7a(3) =15a(4) =31a(5) =63a(6) =127a(7) =255a(8) =511a(9) =8191a(10) =16383a(11) =32767a(12) =65535a(13) =262143a(14) =524287a(15) =16777215a(16) =33554431a(17) =134217727a(18) =268435455a(19) =2147483647a(20) =4294967295a(21) =8589934591a(22) =17179869183a(23) =34359738367a(24) =68719476735a(25) =137438953471a(26) =549755813887