a(n) is the least exponent k greater than 1 such that prime(n)^k starts and ends in prime(n).

Terms

a(0) =21a(1) =41a(2) =24a(3) =33a(4) =171a(5) =361a(6) =461a(7) =471a(8) =1281a(9) =1091a(10) =231a(11) =221a(12) =236a(13) =61a(14) =861a(15) =2761a(16) =241a(17) =546a(18) =3261a(19) =1991a(20) =6081a(21) =421a(22) =9541a(23) =5731a(24) =4461a(25) =1621a(26) =21501a(27) =10381a(28) =5051a(29) =1301