Problems & Puzzles: Puzzles

Puzzle 465. Factorials Farideh sent the following nice puzzle: π(13)=1!*3! π(226130351)=2!*2!*6!*1!*3!*0!*3!*5!*1! Q. What is the next prime (see A066457)?

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On Dec 08 Qu, Shun Liang wrote:

I have search up to 2*10^14, and find none of them.

I found 209210612202, 209210612212, 209210612220, 209210612221, ( A066457 )

But unfortunately，all of them are composite number. I think there will be a number in 10^18, but it too hard to reach. A discussion about this problem: http://bbs.emath.ac.cn/thread-918-1-1.html

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