1 ((k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(c - I*k0)^2])*(c - I*k0)^6)/(6*k^6) - (5*(k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(2*c - I*k0)^2])*(2*c - I*k0)^6))/(6*k^6) + (5*(k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(3*c - I*k0)^2])*(3*c - I*k0)^6))/(3*k^6) - (5*(k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(4*c - I*k0)^2])*(4*c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(4*c - I*k0)^2])*(4*c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(4*c - I*k0)^2])*(4*c - I*k0)^6))/(3*k^6) + (5*(k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(5*c - I*k0)^2])*(5*c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(5*c - I*k0)^2])*(5*c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(5*c - I*k0)^2])*(5*c - I*k0)^6))/(6*k^6) - (k^6 - 6*k^4*(-3 + Sqrt[1 + k^2/(6*c - I*k0)^2])*(6*c - I*k0)^2 + 16*k^2*(3 - 2*Sqrt[1 + k^2/(6*c - I*k0)^2])*(6*c - I*k0)^4 - 32*(-1 + Sqrt[1 + k^2/(6*c - I*k0)^2])*(6*c - I*k0)^6)/(6*k^6))/k0^2
2 SeriesData[k, Infinity, {(945*c^5)/k0^2, (-13440*c^6)/k0^2 + ((3840*I)*c^5)/k0, (-10395*c^5)/2 + (65835*c^7)/k0^2 - ((72765*I)/2*c^6)/k0, 0, (-15015*(1087*c^9 - (1134*I)*c^8*k0 - 456*c^7*k0^2 + (84*I)*c^6*k0^3 + 6*c^5*k0^4))/(16*k0^2)}, 5, 11, 1]