187485

Appears in sequences

• Quasi-Carmichael numbers to base -3: squarefree composites n such that for every prime p that divides n, p+3 divides n+3.at n=18A029563
• G.f.: A(x) = INV(x - x*INV(x - 3*x*INV(x - 3^2*x*INV(x - 3^3*x*INV(x - 3^4*x*INV(x - ...)))))), where INV(F(x)) = series reversion of F(x).at n=5A195196
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having one, two, three, four, five or six distinct values for every i,j,k<=n.at n=8A211581