4189184

Appears in sequences

• Numbers n such that phi(n) + 1 | sigma(n).at n=16A056097
• Numbers k such that sigma(k) == 4 (mod phi(k)).at n=10A067193
• Let M be the 3 X 3 Matrix [ -4 4 8 / 1 0 0 / 0 1 0], a(n) = absolute value of the center term of M^n * [1 1 1].at n=10A094253
• Expansion of (4 - 7*x + 2*x^2)/((1-2*x)*(1 - 2*x + 2*x^2)).at n=21A100215