The Gospels mention Jesus going up a mountain to pray on several occasions. Here are a few examples:
* Matthew 14:23 & Mark 6:46: After feeding the 5,000, Jesus went up a mountain by himself to pray. This doesn't specify how many times He prayed during that period.
* Luke 6:12: Before choosing the twelve apostles, Jesus went out to a mountainside to pray, and spent the night praying to God. This doesn't specify how many times He prayed, but indicates a prolonged period of prayer.
* The Mount of Transfiguration (Matthew 17:1, Mark 9:2, Luke 9:28): While the primary focus isn't on Jesus praying, Luke 9:29 mentions that the transfiguration happened "as he was praying."
* The Garden of Gethsemane (Matthew 26:36-46, Mark 14:32-42, Luke 22:39-46): Before his arrest, Jesus went to the Garden of Gethsemane and prayed three times, asking that the cup of suffering be taken from him, but ultimately submitting to God's will.
So, the number of times Jesus prayed on a mountain depends on which instance you are referring to. The Garden of Gethsemane is the only place where the Gospels specifically state that He prayed multiple times (three). Other accounts mention Him going to mountains to pray without specifying the number of times He prayed.