a(n) = prime(n)^2 - 4*prime(n).

Terms

a(0) =5a(1) =21a(2) =77a(3) =117a(4) =221a(5) =285a(6) =437a(7) =725a(8) =837a(9) =1221a(10) =1517a(11) =1677a(12) =2021a(13) =2597a(14) =3245a(15) =3477a(16) =4221a(17) =4757a(18) =5037a(19) =5925a(20) =6557a(21) =7565a(22) =9021a(23) =9797a(24) =10197a(25) =11021a(26) =11445a(27) =12317a(28) =15621a(29) =16637