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We report recent improvement in absolute frequency measurement of the 115In+5s2 1S0-5s5p 3P0 clock transition at 236.5 nm. Using a narrowline laser as a local oscillator, a linewidth of 43 Hz for the transition is resolved. The uncertainty of the transition frequency's centroid is 18 Hz, leading to a fractional uncertainty of 1.4 x 10-14. In the experiment, a single 115In+is trapped in a three-ring Paul-Straubel trap and laser cooled to the trap's vibrational ground states.