5 times pentagonal numbers: 5*n*(3*n-1)/2.

Terms

a(0) =0a(1) =5a(2) =25a(3) =60a(4) =110a(5) =175a(6) =255a(7) =350a(8) =460a(9) =585a(10) =725a(11) =880a(12) =1050a(13) =1235a(14) =1435a(15) =1650a(16) =1880a(17) =2125a(18) =2385a(19) =2660a(20) =2950a(21) =3255a(22) =3575a(23) =3910a(24) =4260a(25) =4625a(26) =5005a(27) =5400a(28) =5810a(29) =6235