Least prime p such that prime(p*n)-1 is a square, or 0 if no such p exists.

Terms

a(0) =3a(1) =13a(2) =41a(3) =3a(4) =11a(5) =2a(6) =241a(7) =181a(8) =5a(9) =2927a(10) =5a(11) =523a(12) =2a(13) =4967a(14) =3a(15) =421a(16) =33053a(17) =8447a(18) =17107a(19) =20747a(20) =1811a(21) =5743a(22) =20407a(23) =99643a(24) =165443a(25) =769a(26) =21269a(27) =46099a(28) =3121a(29) =9883