a(1)=2 because prime(2^3)-2 = 19-2 = 17 and 17 is prime,
a(2)=4 because prime(4^3)-4 = 311-4 = 307 and 307 is prime,
a(3)=12 because prime(12^3)-12 = 14741 and 14741 is prime, ...
MAPLE
ts_pra_3:=proc(n) local i, ans; ans := [ ]: for i from 1 to n do if (isprime(ithprime(i^(3))-i)) then ans := [ op(ans), i ]: fi: od; RETURN(ans) end: ts_pra_3(200);
CROSSREFS
Cf. A064269 - prime(n)-n is prime, A105962 - prime(n^2)-n is prime.
