Numbers k such that k + 1 has one more divisor than k.

Terms

a(0) =1a(1) =3a(2) =9a(3) =15a(4) =25a(5) =63a(6) =121a(7) =195a(8) =255a(9) =361a(10) =483a(11) =729a(12) =841a(13) =1443a(14) =3363a(15) =3481a(16) =3721a(17) =5041a(18) =6241a(19) =10201a(20) =15625a(21) =17161a(22) =18224a(23) =19321a(24) =24963a(25) =31683a(26) =32761a(27) =39601a(28) =58564a(29) =59049