配置cron每15分钟运行一次URL [关闭]

I'd like to set up a cron job to go to a URL every 15 minutes. I have a VPS with centos 6 on it and access to SSH. This is what I have tried so far with no luck:

1. In ssh, type "crontab -e"
2. * /15 * * * * wget (URL HERE)
3. Hit 'ESC' and type ":wq" to save work and exit

I'm sure theres something wrong with the way I'm writting this out.

There should be no space between the range and the step.

*/15