1 (k^2*(3 - 2*Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^2 - 2*(-1 + Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^4 + 3*k^2*(-3 + 2*Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^2 + 6*(-1 + Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^4 + 3*k^2*(3 - 2*Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0)^2 - 6*(-1 + Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0)^4 + k^2*(-3 + 2*Sqrt[1 + k^2/(4*c - I*k0)^2])*(4*c - I*k0)^2 + 2*(-1 + Sqrt[1 + k^2/(4*c - I*k0)^2])*(4*c - I*k0)^4)/(6*k^3*k0^3)
2 SeriesData[k, Infinity, {(3*c^3)/k0^3, (-20*c^4)/k0^3 + ((8*I)*c^3)/k0^2, (15*(13*c^5 - (10*I)*c^4*k0 - 2*c^3*k0^2))/(4*k0^3), 0, (-7*(243*c^7 - (350*I)*c^6*k0 - 195*c^5*k0^2 + (50*I)*c^4*k0^3 + 5*c^3*k0^4))/(8*k0^3), 0, (3*(34105*c^9 - (69930*I)*c^8*k0 - 61236*c^7*k0^2 + (29400*I)*c^6*k0^3 + 8190*c^5*k0^4 - (1260*I)*c^4*k0^5 - 84*c^3*k0^6))/(64*k0^3), 0, (-33*(55591*c^11 - (145750*I)*c^10*k0 - 170525*c^9*k0^2 + (116550*I)*c^8*k0^3 + 51030*c^7*k0^4 - (14700*I)*c^6*k0^5 - 2730*c^5*k0^6 + (300*I)*c^4*k0^7 + 15*c^3*k0^8))/(128*k0^3)}, 2, 11, 1]