33×37.43×47.59×57.63×67.73×77.的规律

33×37.43×47.59×57.63×67.73×77.的规律
2025-04-13 05:20:45
推荐回答(1个)
回答1:

33×37 43×47 53×57 63×67 73×77……
(33+(n一1)*10)×(37+(n一1)*10)……
an=(10n+3)x(10n+7)
=100n^2+100n十21