Number of nodes at the n-th level of the Inverse-Totient-Tree (ITT) with the root at 1, and edges connecting number m to all numbers k such that phi(k) = m.

A058811

Number of nodes at the n-th level of the Inverse-Totient-Tree (ITT) with the root at 1, and edges connecting number m to all numbers k such that phi(k) = m.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =8a(4) =17a(5) =41a(6) =92a(7) =215a(8) =487a(9) =1126a(10) =2583a(11) =5981a(12) =13698a(13) =31647a(14) =72678a(15) =167474a(16) =385021a(17) =887133a(18) =2041375a(19) =4700526a(20) =10817997a(21) =24908164a(22) =57334111a(23) =131995229

External references