A parameter-free vacuum-energy ratio inside the observed band

The cosmological constant problem is usually stated as a mismatch of more than a hundred orders of magnitude between a vacuum-energy estimate and the observed expansion rate. In this framework the comparison reduces to one exact rational with no fitted quantity in it. The theory's vacuum energy is _eff=_CM^4e^- S^ with S^=1502, and it equals 4.8310^-47\ GeV^4. Divided by a single sealed rational, it lies inside the observed band. That rational is G_1=(45/24)/(1+x)=28125/15128=1.8591353781. Its three components are independent structural counts. Here 45 counts the components of the 105 product, 24 is the adjoint dimension, and x=16/1875 is the sealed multiplier expectation value. Whether G_1 is the mechanism of the placement, rather than an arithmetic identity that happens to sit in the right band, remains open. It is put forward as a candidate [c] with a pre-registered falsifiable test protocol. An earlier degree-of-freedom narrative for the same ratio was deleted from the archive as a mislabelling. Three observational readings of the band are displayed with their deviations (1.83\%, 3.37\%, 12.5\%). The differences between them are attributed to the cosmological data sets that define them. No measured number enters any derivation. –-