Indices of primes in sequence defined by A(0) = 71, A(n) = 10*A(n-1) + 21 for n > 0.

Terms

a(0) =0a(1) =2a(2) =3a(3) =4a(4) =5a(5) =8a(6) =11a(7) =30a(8) =58a(9) =68a(10) =73a(11) =286a(12) =488a(13) =591a(14) =633a(15) =1088a(16) =1606a(17) =3140a(18) =5961a(19) =6266a(20) =9677a(21) =11430a(22) =12926a(23) =32188a(24) =38699a(25) =53032a(26) =83524a(27) =185949