Tn=n(n+1)/2
Tn-1 = (n+2)(n-1)/2
Tn-1 -1 = (n+1)(n-2)/2
TnTn-1 - 1 = nn-2
taking products of terms we get
T2*314253....19911899
= 3*0.5*1990*1991
= 5943135
Let
Tn = 1 + 2 + 3 + · · · + n and
Pn =T2T2-1.T3T3-1.T4T4-1.......TnTn-1
Find Pn????
Tn=n(n+1)/2
Tn-1 = (n+2)(n-1)/2
Tn-1 -1 = (n+1)(n-2)/2
TnTn-1 - 1 = nn-2
taking products of terms we get
T2*314253....19911899
= 3*0.5*1990*1991
= 5943135