等差数列前n项和为Sn且a3a4=117,a2+a5=22,求通项an 若等差数列bn=Sn/（n+c）,求非零常数c（d大于0）非零常数c呢

等差数列前n项和为Sn且a3a4=117,a2+a5=22,求通项an 若等差数列bn=Sn/（n+c）,求非零常数c（d大于0）非零常数c呢 已知公差大于零的等差数列{an}的前n项和为sn,且满足a3a4=117,a2+a5=22.求数列{an}的通项公式? 已知公差大于0的等差数列{An}的前n项和为Sn,且满足a3a4=117,a2+a5=22,1.求通向公式An.2.若{Bn}为等差数,且Bn=Sn/n+c,求非零常数cBn=Sn/(n+c) 已知公差大于零的等差数列{an},前n项和为Sn,且满足a3a4=117,a2+a5=22一、求数列{an}的通项公式二、若bn=(sn)/(n-1/2),求f(n)=(bn)/[(n+36)b脚标n+1] (n属于N*)的最大值 已知公差大于零的等差数列an前n项和为Sn,且满足a3a4=-3,a2+a5=2.（1）求通项an（2）求Sn的最小值（3）若数列bn是等差数列,且bn=Sn／n+c,求非零常数c 等差数列｛an｝前n项和为Sn,且Sn=3n^2+n 求公差d 已知数列{bn}前n项和为Sn,且2(Sn-n)=n*bn,求证{bn}是等差数列. 等差数列an的前n项和为Sn,已知Sm=a,Sn-Sn-m=b,m、n属于自然数且n>m,求Sn? 设等差数列an前n项和为sn,且s10=s20.则s30=? 等差数列{an}的前n项和为Sn,且S10-S5=3,S15=? 等差数列前n项和为Sn,且a1=12,S12>0,S13 等差数列an的前n项和为Sn,且a5+a21=a12,求S27 等差数列an的前n项和为sn 且s7=7 则a2+a6 在等差数列{an}中,设前m项和为Sm,前n项和为Sn,且Sm=Sn,m不等于n,则Sm+n=? 等差数列an的前n项和为Sn,且Sn=30,S2n=90,则S3n=? 设等差数列{an}前n项和为Sn,且a1>0,S13=S19,求Sn的最大值 设等差数列{an}的前n项和为Sn,且S5=-5,S10=15,求数列{Sn/n}的前n项和Tn 等差数列{an}的前n项和为Sn,且S5=-5,S10=15,求数列{Sn/n}的前n项和T