數(shù)學都還給老師了...我的邏輯對不上啊...不是吃了一半再加1么，（（n+1）+1）*2不太理解

#include <stdio.h>
int getPeachNumber(int n)
{
??? int num;??? //?¨ò??ùê￡ìò×óêy
??? if(n==10)
??? {
?????? return 1;?????? //μY1é?áê?ì??t
??? }
??? else
??? {
??????? num = getPeachNumber(n+1)*2+1
???;?? //?aà?ê?2?ó|??ó?μY1é??￡?
??????? printf("μú%dìì?ùê￡ìò×ó%d??\n", n, num); //ììêy￡??ùê￡ìò×ó??êy
??? }
??? return num;
}
int main()
{
??? int num = getPeachNumber(1);
??? printf("o?×óμúò?ìì?aá?:%d??ìò×ó?￡\n", num);
??? return 0;
}