Number of divisors of p+1, p prime.

Terms

a(0) =2a(1) =3a(2) =4a(3) =4a(4) =6a(5) =4a(6) =6a(7) =6a(8) =8a(9) =8a(10) =6a(11) =4a(12) =8a(13) =6a(14) =10a(15) =8a(16) =12a(17) =4a(18) =6a(19) =12a(20) =4a(21) =10a(22) =12a(23) =12a(24) =6a(25) =8a(26) =8a(27) =12a(28) =8a(29) =8