L.H.S.
= nC0 + 3.C1 + 5.C2 + … + (2n + 1) nCn
= nC0 + (2 + 1) nC1 + (4 + 1) nC2 + … (2n + 1) nCn
= nC0 + (2. nC1 + nC1 + (4. nC2 + nC2) + … (2n.nCn + nCn)
= 2. nC1 + 4 nC2 + 6 nC3 + … + 2n nCn
+ (nC0 + nC1 + nC2 + nC3 + …nCn)
= 2[nC1 + 2 nC2 + 3.nC3 +… + nCn] + (1 + 1)n