a(n) = 74*n^2 + 1.

Terms

a(0) =1a(1) =75a(2) =297a(3) =667a(4) =1185a(5) =1851a(6) =2665a(7) =3627a(8) =4737a(9) =5995a(10) =7401a(11) =8955a(12) =10657a(13) =12507a(14) =14505a(15) =16651a(16) =18945a(17) =21387a(18) =23977a(19) =26715a(20) =29601a(21) =32635a(22) =35817a(23) =39147a(24) =42625a(25) =46251a(26) =50025a(27) =53947a(28) =58017a(29) =62235