a(n) = floor(5*prime(n)^2 / 4).

Terms

a(0) =5a(1) =11a(2) =31a(3) =61a(4) =151a(5) =211a(6) =361a(7) =451a(8) =661a(9) =1051a(10) =1201a(11) =1711a(12) =2101a(13) =2311a(14) =2761a(15) =3511a(16) =4351a(17) =4651a(18) =5611a(19) =6301a(20) =6661a(21) =7801a(22) =8611a(23) =9901a(24) =11761a(25) =12751a(26) =13261a(27) =14311a(28) =14851a(29) =15961