Twice 12-gonal numbers: a(n) = 2*n*(5*n-4).

Terms

a(0) =0a(1) =2a(2) =24a(3) =66a(4) =128a(5) =210a(6) =312a(7) =434a(8) =576a(9) =738a(10) =920a(11) =1122a(12) =1344a(13) =1586a(14) =1848a(15) =2130a(16) =2432a(17) =2754a(18) =3096a(19) =3458a(20) =3840a(21) =4242a(22) =4664a(23) =5106a(24) =5568a(25) =6050a(26) =6552a(27) =7074a(28) =7616a(29) =8178