问题
选择题
已知等差数列{an}和{bn}的前n项和分别为An和Bn，且
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答案
=an bn
=2an 2bn
=n(a1+a2n-1) 2 n(b1+b2n-1) 2
=A2n-1 B2n-1
=14n+34 2n+2
=7+7n+17 n+1 10 n+1
验证知，当n=1，4，9时
为整数的正整数an bn
故选：B
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已知等差数列{an}和{bn}的前n项和分别为An和Bn，且
|
=an bn
=2an 2bn
=n(a1+a2n-1) 2 n(b1+b2n-1) 2
=A2n-1 B2n-1
=14n+34 2n+2
=7+7n+17 n+1 10 n+1
验证知，当n=1，4，9时
为整数的正整数an bn
故选：B