∫(1+x)n=∫nC0x0+nC1x1+nC2x2+........nCnxn
∫(1+x)n(n+1)=∫C0x1+C1x22+C2x33+........Cnxn+1n+1
∫(1+x)n=∫nC0x0+nC1x1+nC2x2+........nCnxn
(1+x)n+1(n+1)(n+2)=C0x1.2+C1x22.3+C2x33.4+........Cnxn+2(n+1)(n+2)
Put x=1
2n+1(n+1)(n+2)=C0x1.2+C1x22.3+C2x33.4+........Cnxn+2(n+1)(n+2)