OFFSET
0,6
FORMULA
G.f.: 1/(Sum_{j>=0} phi(j+1)*x^j*(1-x)).
MATHEMATICA
T[n_, k_] := If[k <= n, EulerPhi[n - k + 1], 0]; With[{max = 48}, Tinv = Inverse[Table[T[n, k], {n, 0, max - 1}, {k, 0, max - 1}]]; Total[Transpose[Table[Tinv[[n, k]], {n, 1, max}, {k, 1, max}]]]] (* Amiram Eldar, Nov 16 2024 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, May 03 2005
STATUS
approved