a(n) = 2*n^3 - 4*n^2 + 6*n - 2 (n>=1).

Terms

a(0) =2a(1) =10a(2) =34a(3) =86a(4) =178a(5) =322a(6) =530a(7) =814a(8) =1186a(9) =1658a(10) =2242a(11) =2950a(12) =3794a(13) =4786a(14) =5938a(15) =7262a(16) =8770a(17) =10474a(18) =12386a(19) =14518a(20) =16882a(21) =19490a(22) =22354a(23) =25486a(24) =28898a(25) =32602a(26) =36610a(27) =40934a(28) =45586a(29) =50578