Number of n-digit 7th powers.

Terms

a(0) =2a(1) =0a(2) =1a(3) =1a(4) =2a(5) =2a(6) =2a(7) =4a(8) =6a(9) =7a(10) =11a(11) =14a(12) =20a(13) =28a(14) =39a(15) =55a(16) =75a(17) =104a(18) =145a(19) =202a(20) =280a(21) =390a(22) =541a(23) =752a(24) =1045a(25) =1452a(26) =2017a(27) =2803a(28) =3895a(29) =5412