Least n-digit 'happy' prime.

Terms

a(0) =7a(1) =13a(2) =103a(3) =1009a(4) =10009a(5) =100003a(6) =1000003a(7) =10000121a(8) =100000039a(9) =1000000009a(10) =10000000033a(11) =100000000003