This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A106480 #9 Nov 16 2024 02:56:49
%S A106480 1,0,-1,0,-1,2,-1,-2,5,-4,1,0,-7,18,-9,-12,17,-24,31,6,-67,94,-49,-60,
%T A106480 157,-230,217,118,-619,758,-461,-252,1509,-2490,1867,780,-4531,6932,
%U A106480 -5543,-820,11885,-21248,17591,2586,-32415,58070,-54325,-56
%N A106480 Row sums of inverse of sequence array for Euler phi function.
%F A106480 G.f.: 1/(Sum_{j>=0} phi(j+1)*x^j*(1-x)).
%t A106480 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 *)
%Y A106480 Cf. A000010, A106476, A106477, A106478, A106479.
%K A106480 easy,sign
%O A106480 0,6
%A A106480 _Paul Barry_, May 03 2005