Smallest prime whose product of digits is 2^n.

Terms

a(0) =11a(1) =2a(2) =41a(3) =181a(4) =281a(5) =1481a(6) =881a(7) =4481a(8) =18481a(9) =48281a(10) =48481a(11) =228881a(12) =284881a(13) =828881a(14) =884881a(15) =4448881a(16) =4848881a(17) =18848881a(18) =24888881a(19) =48888841a(20) =88884881a(21) =188888881a(22) =888828881a(23) =848888881a(24) =4848488881a(25) =4488888881a(26) =18848888881a(27) =28888884881