Centered 30-gonal numbers.

Terms

a(0) =1a(1) =31a(2) =91a(3) =181a(4) =301a(5) =451a(6) =631a(7) =841a(8) =1081a(9) =1351a(10) =1651a(11) =1981a(12) =2341a(13) =2731a(14) =3151a(15) =3601a(16) =4081a(17) =4591a(18) =5131a(19) =5701a(20) =6301a(21) =6931a(22) =7591a(23) =8281a(24) =9001a(25) =9751a(26) =10531a(27) =11341a(28) =12181a(29) =13051