a(n) is the number of unordered pairs of perfect powers whose product equals n^n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =2a(5) =11a(6) =3a(7) =12a(8) =9a(9) =22a(10) =5a(11) =62a(12) =6a(13) =37a(14) =27a(15) =32a(16) =8a(17) =129a(18) =9a(19) =135a(20) =45a(21) =79a(22) =11a(23) =325a(24) =25a(25) =108a(26) =40a(27) =244a(28) =14a(29) =2739