a(n) = 4*(5*n^2 - 5*n + 1).

Terms

a(0) =4a(1) =44a(2) =124a(3) =244a(4) =404a(5) =604a(6) =844a(7) =1124a(8) =1444a(9) =1804a(10) =2204a(11) =2644a(12) =3124a(13) =3644a(14) =4204a(15) =4804a(16) =5444a(17) =6124a(18) =6844a(19) =7604a(20) =8404a(21) =9244a(22) =10124a(23) =11044a(24) =12004a(25) =13004a(26) =14044a(27) =15124a(28) =16244a(29) =17404