Sum of number of divisors of x^y for each x >= 1, y >= 0, x + y = n.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =12a(5) =18a(6) =27a(7) =39a(8) =56a(9) =77a(10) =103a(11) =134a(12) =174a(13) =223a(14) =283a(15) =356a(16) =445a(17) =547a(18) =666a(19) =802a(20) =959a(21) =1139a(22) =1344a(23) =1574a(24) =1835a(25) =2128a(26) =2454a(27) =2815a(28) =3213a(29) =3648