当n=5时,具有5个顶部拱和2个外部顶部拱的半弯道数量等于A259689型(5,2) = 6:
__ __
//\\ __ ____ //\\ __ ____
///\\\ __ //\\ / /\\ ///\\\ //\\ __ //\ \
/\////\\\\, //\\///\\\, /\//\//\\\, ////\\\\/\, ///\\\//\\, ///\\/\\/\
这6种解决方案共有12个外拱。
使用外拱分割算法的n+1代解决方案:
__
//\\ __ ____
///\\\ __ //\\ __ /____\
////\\\\ __ //\\ ///\\\ //\\ __ // __\\ __ __
/\/////\\\\\,//\\///\\\/\,/\/\////\\\\,///\\\//\\/\,/\///\//\\\\,//\\/\//\\/\
__
//\\ __ ____
///\\\ __ //\\ __ /____\
////\\\\ //\\ __ ///\\\ __ //\\ //__ \\ __ __
/////\\\\\/\,/\///\\\//\\,////\\\\/\/\,/\//\\///\\\,////\\/\\\/\,/\//\\/\//\\
这12个解决方案有34个外拱。因此a(5)=34。