这个数列题要怎么解？求详细过程，谢谢大家~\(≧▽≦)/~
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a(n+1)= 2an+3^n
a(n+1)/2^(n+1)- an/2^n = (1/2)(3/2)^n
an/2^n- a(n-1)/2^(n-1) = (1/2)(3/2)^(n-1)
an/2^n- a1/2^1 = (1/2)[ (3/2)^1+(3/2)^2+...+(3/2)^(n-1) ]
an/2^n = (1/2)[ (3/2)^0+(3/2)^1+...+(3/2)^(n-1) ]
= -1+(3/2)^n
an = [ -1+(3/2)^n ]. 2^n
= 3^n -2^n
a(n+1)/2^(n+1)- an/2^n = (1/2)(3/2)^n
an/2^n- a(n-1)/2^(n-1) = (1/2)(3/2)^(n-1)
an/2^n- a1/2^1 = (1/2)[ (3/2)^1+(3/2)^2+...+(3/2)^(n-1) ]
an/2^n = (1/2)[ (3/2)^0+(3/2)^1+...+(3/2)^(n-1) ]
= -1+(3/2)^n
an = [ -1+(3/2)^n ]. 2^n
= 3^n -2^n
追问
那个小小的尖尖是什么意思啊
追答
3^n：3的n次方
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