1 (6*(3 - 2*Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0) - (12*(-1 + Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^3)/k^2 + 6*(-3 + 2*Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0) + (12*(-1 + Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^3)/k^2 + 2*(3 - 2*Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0) - (4*(-1 + Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*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, {(2*c^3)/k0^3, (-9*c^4)/(2*k0^3) + ((3*I)*c^3)/k0^2, 0, (5*(9*c^6 - (15*I)*c^5*k0 - 9*c^4*k0^2 + (2*I)*c^3*k0^3))/(4*k0^3), 0, (-21*(69*c^8 - (172*I)*c^7*k0 - 180*c^6*k0^2 + (100*I)*c^5*k0^3 + 30*c^4*k0^4 - (4*I)*c^3*k0^5))/(32*k0^3), 0, (15*(933*c^10 - (3025*I)*c^9*k0 - 4347*c^8*k0^2 + (3612*I)*c^7*k0^3 + 1890*c^6*k0^4 - (630*I)*c^5*k0^5 - 126*c^4*k0^6 + (12*I)*c^3*k0^7))/(64*k0^3)}, 2, 11, 1]