The spin only magnetic moment of cobalt in the compound Hg[Co(SCN)4] is _____ ?

In the complex Hg[Co(SCN)4], Co is in +2 oxidation state.Electronic configuration of Co(II) :Ar4s03d7Now thiocyanato is a weak field ligand and so there will be no back pairing.Spin only magnetic moment is given as μm=n(n+2) BMPutting n=3, we get μm=15BM