1 (-4*(-3 + 2*Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0) - (8*(-1 + Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^3)/k^2 + 2*(-3 + 2*Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0) + (4*(-1 + Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^3)/k^2 + 3*k0*Sqrt[Pi]*(Piecewise[{{0, k^2/k0^2 <= 1}}, (4*(k^2 - k0^2)^(3/2))/(3*k^2*k0*Sqrt[Pi])] + I*Piecewise[{{(-2*(2*k0*(k0 - Sqrt[-k^2 + k0^2]) + k^2*(-3 + (2*Sqrt[-k^2 + k0^2])/k0)))/(3*k^2*Sqrt[Pi]), k^2/k0^2 < 1}, {(2*(1 - (2*k0^2)/(3*k^2)))/Sqrt[Pi], k^2/k0^2 > 1}}, 0]))/(12*k0^3)
2 SeriesData[k, Infinity, {c^2/k0^3, (-2*(c^3 - I*c^2*k0))/k0^3, (7*c^4 - (12*I)*c^3*k0 - 6*c^2*k0^2)/(4*k0^3), 0, (-31*c^6 + (90*I)*c^5*k0 + 105*c^4*k0^2 - (60*I)*c^3*k0^3 - 15*c^2*k0^4)/(24*k0^3), 0, (127*c^8 - (504*I)*c^7*k0 - 868*c^6*k0^2 + (840*I)*c^5*k0^3 + 490*c^4*k0^4 - (168*I)*c^3*k0^5 - 28*c^2*k0^6)/(64*k0^3), 0, (-511*c^10 + (2550*I)*c^9*k0 + 5715*c^8*k0^2 - (7560*I)*c^7*k0^3 - 6510*c^6*k0^4 + (3780*I)*c^5*k0^5 + 1470*c^4*k0^6 - (360*I)*c^3*k0^7 - 45*c^2*k0^8)/(128*k0^3)}, 1, 11, 1]