Data from two frequency ranges within the Q-band observed with the Yebes 40 m telescope towards IRC +10216. Each frequency range is shown through two panels with different limits in intensity. The vertical scale is antenna temperature in mK. The horizontal scale is the rest frequency in MHz. Labels for HC₇N features are in blue, while those belonging to HC₉N are in violet. Other spectral features from known species, together with unidentified lines (labeled as “U” lines), are indicated in red. The N = 16−15 doublet of MgCCCN, a new species recently detected (Cernicharo et al. 2019), is shown in the bottom panels. Vibrationally excited lines from HC₇N, HC₉N, and C₆H are nicely detected at these frequencies. Additional lines from vibrationally excited states of HC₅N, HC₇N, and HC₉N are shown in Figs. 2, A.1, and A.3.