Prime numbers whose digits are k+1 1's and k 2's for some k >= 1.

Terms

a(0) =211a(1) =12211a(2) =21121a(3) =21211a(4) =22111a(5) =1121221a(6) =1212121a(7) =2121121a(8) =2211211a(9) =2221111a(10) =111221221a(11) =112212211a(12) =112221211a(13) =121211221a(14) =211122211a(15) =211212121a(16) =211222111a(17) =221112121a(18) =221212111a(19) =11122121221a(20) =11122221211a(21) =11211221221a(22) =11212211221a(23) =11212221121a(24) =11222112211