10 times pentagonal numbers: a(n) = 5*n*(3*n-1).

Terms

a(0) =0a(1) =10a(2) =50a(3) =120a(4) =220a(5) =350a(6) =510a(7) =700a(8) =920a(9) =1170a(10) =1450a(11) =1760a(12) =2100a(13) =2470a(14) =2870a(15) =3300a(16) =3760a(17) =4250a(18) =4770a(19) =5320a(20) =5900a(21) =6510a(22) =7150a(23) =7820a(24) =8520a(25) =9250a(26) =10010a(27) =10800a(28) =11620a(29) =12470