Mean flux densities (dots and circles) and upper limits for flux densities (triangles) as reported in Table 5 for the 29 pulsars whose timing positions fall within the FWHM of the LOFAR Core tied-array beam. Filled dots and triangles are flux density measurements for which five or more observations were available, while empty circles and triangles are measurements from less than five observations. The black lines represent fitted spectral indices, which are the mean values for the spectral index α and the flux density on the reference frequency of 149 MHz S​₀ from the EMCEE samples. The shaded regions represent the uncertainty on α and S​₀ propagated to flux densities between 90 and 2100 MHz. For the spectral index fit, only flux density measurements with five or more observations were used.