After opening the little blue whales are to hold the party in order to want to make friends, but because of the outbreak, the need to control the number of the party, so the organizers put forward a solution to select small blue whale can party, all line up, one by one, everyone get a number, the first no. 2, no. 3, the second and the third number 4, so on, the first small blue whale say his number two, don't quit, you can participate in the party, but behind him every two (such as number of 4,6,8) small blue whale must leave the party, the rest of the team in a small blue whale say his number 3, he may take part in the party, but behind him every three (the number is 9,15,21, etc.) small blue whale had to leave, the rest of the team the next little blue whale speak his number 5, he may take part in the party, but behind him every 5 (the number is 19,35,49, etc.) small blue whales have to leave the party, the next number is 7, he can continue to party, but behind him every seven have to leave, so on, according to the plan, to participate in party lucky little blue number is 2,3,5,7,11,13,17 etc, now, would you please find the NTH lucky number,

CodePudding user response:

Actually is not o n a prime number