Some of these intervals seemed familiar to me, and I realized that they're basically the same as those in "Day after Day (The Show Must Go On)," played on what the APP website calls "jangle piano." It's also doubled with a synthesizer. These phrases repeat through much of the verse:
The phrases in the two songs begin in different places and have a different number of notes, but each consists of a root note, the fourth, the fifth, and the octave. In "Sirius," the order is fourth, fifth, octave, root (with the seventh substituted for the octave every other time); in "Day after Day," it's octave, fifth, fourth, root, fourth, fifth. Obviously, the parts aren't the same, but they do have the same sort of musical vocabulary.