10 times triangular numbers: a(n) = 5*n*(n + 1).

Terms

a(0) =0a(1) =10a(2) =30a(3) =60a(4) =100a(5) =150a(6) =210a(7) =280a(8) =360a(9) =450a(10) =550a(11) =660a(12) =780a(13) =910a(14) =1050a(15) =1200a(16) =1360a(17) =1530a(18) =1710a(19) =1900a(20) =2100a(21) =2310a(22) =2530a(23) =2760a(24) =3000a(25) =3250a(26) =3510a(27) =3780a(28) =4060a(29) =4350