5 times hexagonal numbers: 5*n*(2*n-1).

Terms

a(0) =0a(1) =5a(2) =30a(3) =75a(4) =140a(5) =225a(6) =330a(7) =455a(8) =600a(9) =765a(10) =950a(11) =1155a(12) =1380a(13) =1625a(14) =1890a(15) =2175a(16) =2480a(17) =2805a(18) =3150a(19) =3515a(20) =3900a(21) =4305a(22) =4730a(23) =5175a(24) =5640a(25) =6125a(26) =6630a(27) =7155a(28) =7700a(29) =8265