在数列an中a1=1,an+1=3an+2∧n+3n²–1,求an的通项公式

a(n+1)=3an+2ⁿ+3n²-1a(n+1)+2^(n+1)+(3/2)(n+1)² +(3/2)(n+1)+1=3an+3×2ⁿ+(9/2)n²+(9/2)n+3[a(n+1)+2^(n+1)+(3/2)(n+1)² +(3/2)(n+1)+1]/[an+2ⁿ+(3/2)n²+(3/2)n+1]=3,...