15/05/29 03:57:23.43 cH3C4K+Q.net
>>406
mが自然数の時|a_m| < 1, n>2ならば
0 < Σ[k=1,n-1](1-a_(k+1))(1-Π[i=1,k]a_i)
= Σ[k=1,n-1]{ 1 - a_(k+1) - Π[i=1,k]a_i + Π[i=1,k+1]a_i }
= a_1a_2...a_n + n-1 - (a_1+a_2+...+a_n)
15/05/29 03:57:23.43 cH3C4K+Q.net
>>406
mが自然数の時|a_m| < 1, n>2ならば
0 < Σ[k=1,n-1](1-a_(k+1))(1-Π[i=1,k]a_i)
= Σ[k=1,n-1]{ 1 - a_(k+1) - Π[i=1,k]a_i + Π[i=1,k+1]a_i }
= a_1a_2...a_n + n-1 - (a_1+a_2+...+a_n)