0 votes 0 votes somewhere we seen that formula- How many binary tree possible without labeled =c(2n,n)/n+1. anybody explain how we get this formula. DS binary-tree + – sandeep singh gaur asked Feb 22, 2019 retagged Jul 7, 2019 by Cristine sandeep singh gaur 453 views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply Satbir commented Feb 23, 2019 reply Follow Share This formula is called Catalan number read about it you will understand. 1 votes 1 votes Asim Siddiqui 4 commented Feb 23, 2019 reply Follow Share https://brilliant.org/wiki/catalan-numbers/ 1 votes 1 votes Please log in or register to add a comment.