Number of proper divisors of n-th even perfect number.

Terms

a(0) =3a(1) =5a(2) =9a(3) =13a(4) =25a(5) =33a(6) =37a(7) =61a(8) =121a(9) =177a(10) =213a(11) =253a(12) =1041a(13) =1213a(14) =2557a(15) =4405a(16) =4561a(17) =6433a(18) =8505a(19) =8845a(20) =19377a(21) =19881a(22) =22425a(23) =39873a(24) =43401a(25) =46417a(26) =88993a(27) =172485a(28) =221005a(29) =264097