Centered pentagonal numbers which are squarefree semiprimes.

Terms

a(0) =6a(1) =51a(2) =106a(3) =141a(4) =226a(5) =391a(6) =526a(7) =681a(8) =766a(9) =951a(10) =1501a(11) =1891a(12) =2031a(13) =2326a(14) =2481a(15) =2641a(16) =3151a(17) =3901a(18) =4101a(19) =4306a(20) =6631a(21) =6891a(22) =7981a(23) =8266a(24) =8851a(25) =10081a(26) =10401a(27) =11391a(28) =13141a(29) =14631