Number of powers x^y (x,y > 1) with n digits.

Terms

a(0) =3a(1) =12a(2) =34a(3) =94a(4) =263a(5) =768a(6) =2333a(7) =7167a(8) =22291a(9) =69751a(10) =219081a(11) =689736a(12) =2174856a(13) =6864354a(14) =21679391a(15) =68497906a(16) =216485583a(17) =684323923a(18) =2163459803a(19) =6840258025a(20) =21628220224a(21) =68388917596a(22) =216252901472a(23) =683826283482