a(n) = p^2 - p - 1 where p = prime(n), the n-th prime.

Terms

a(0) =1a(1) =5a(2) =19a(3) =41a(4) =109a(5) =155a(6) =271a(7) =341a(8) =505a(9) =811a(10) =929a(11) =1331a(12) =1639a(13) =1805a(14) =2161a(15) =2755a(16) =3421a(17) =3659a(18) =4421a(19) =4969a(20) =5255a(21) =6161a(22) =6805a(23) =7831a(24) =9311a(25) =10099a(26) =10505a(27) =11341a(28) =11771a(29) =12655