210=2*3*5*7

enzocreti · 2020-02-25, 09:53

Is 210 the only primorial that can be written as n(n-1) with n an integer?

210=15*14

axn · 2020-02-25, 11:38

No.

2=1*2
6=2*3
30=2*3*5=5*6

510510=2*3*5*7*11*13*17=714*715

2020-02-25, 09:53	#1
enzocreti Mar 2018 2·5·53 Posts	*210=2357** Is 210 the only primorial that can be written as n(n-1) with n an integer? 210=15*14

2020-02-25, 11:38	#2
axn Jun 2003 2²·3·421 Posts	No. 2=12 6=23 30=235=56 510510=2357111317=714715 Last fiddled with by axn on 2020-02-25 at 11:40