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#89e14ad9-a08f-4564-b14e-058dddb5e702中等填空题数列求和方法数列

4.(2023•皇姑区四模)设SnS_{n}为数列{an}\{a_{n}\}的前nn项和,若an+an+1=2n1a_{n}+a_{n+1}=2n-1,且存在kNk\in N^{*}Sk=Sk+1=190S_{k}=S_{k+1}=190,则a1a_{1}的取值集合为((  ))