a(n) = 5*n^2 + 20*n + 1.

Terms

a(0) =1a(1) =26a(2) =61a(3) =106a(4) =161a(5) =226a(6) =301a(7) =386a(8) =481a(9) =586a(10) =701a(11) =826a(12) =961a(13) =1106a(14) =1261a(15) =1426a(16) =1601a(17) =1786a(18) =1981a(19) =2186a(20) =2401a(21) =2626a(22) =2861a(23) =3106a(24) =3361a(25) =3626a(26) =3901a(27) =4186a(28) =4481a(29) =4786