Numbers n such that there is exactly one nontrivial square n-gonal number.

Terms

a(0) =34a(1) =74a(2) =100a(3) =130a(4) =202a(5) =244a(6) =290a(7) =394a(8) =452a(9) =514a(10) =650a(11) =724a(12) =802a(13) =970a(14) =1060a(15) =1154a(16) =1354a(17) =1460a(18) =1570a(19) =1802a(20) =1924a(21) =2050a(22) =2314a(23) =2452a(24) =2594a(25) =2890a(26) =3044a(27) =3202a(28) =3364a(29) =3530